Sounds at 85 dBA can cause hearing loss if listened to for more than 8 hours. Sounds above 85 dBA can damage your hearing more quickly. For every 3-dB increase in noise levels above 85 dBA, the safe listening time is cut in half. You can, for example, listen to sounds at 85 dBA for up to 8 hours.
What is meant by decibel?The decibel (dB) is 10 times the decimal logarithm of the ratio of two variables' values. Decibels are calculated using a logarithm, which allows very large or very small relationships to be represented with a conveniently small number. The decibel, abbreviated dB, is the scale's unit. Sound intensity as a reference ( = 10 ^{ -12 } Watts per square meter.) The decibel (dB) is a logarithmic unit of measurement for sound level. It is also widely used in electronics, communications, and signals. The dB is a logarithmic measure of a ratio. Power, sound pressure, voltage, or intensity are all examples of ratios.A noise or sound level of 85 decibels is equivalent to that of a food blender, heavy traffic while driving, a noisy restaurant, or a movie theater. As you can see, we are exposed to high noise levels in a variety of situations in our daily lives.To learn more about decibel, refer to:
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In a trivia game, each correct answer in rounds 1 and 2 is worth 3 points.
The bonus question is worth 5 points. Lily's team had j correct answers in
round 1 and k correct answers in round 2. They answered the bonus
question correctly. What is their score, s? Indicate whether or not each
equation represents the situation.
s=3jk+5
s=3j+3k+5
s=3(j+k)+5
s=3(j+k+5)
Answer:
s=3k+3j+5/s=3(j+k)+5
Step-by-step explanation:
3 x k=3k
3 x j=3j
bonus question:5
total: 3k+3j+5
If you factorize that then you would get 3(j+k)+5
The equation that represents the situation is s = 3(j + k) + 5.
the correct option is C.
What is an equation?Two algebraic expressions having the same value and symbol '=' in between are called an equation.
Given:
In a trivia game, each correct answer in rounds 1 and 2 is worth 3 points.
The bonus question is worth 5 points.
Lily's team had j correct answers in round 1 and k correct answers in round 2.
They answered the bonus question correctly.
That means,
s = 3j + 3k + 5
s = 3(j + k) + 5
Therefore, the equation is s = 3(j + k) + 5.
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Pls help step by step
Answer:
25
Step-by-step explanation:
the tens cancle each other out
How many of kg of mixed nuts that contain 40% peanuts must bill add to 18 kg of mixed nuts that contain 62% peanuts to make a mixture with 52% peanuts
To find, let the no. of kg of mixed nuts that contains 40% peanuts be called [tex]x[/tex].
We know,
Total peanuts already in the mixture = 18 x [tex]\frac{62}{100}[/tex] = 11.16 kg
The new mixture contains 52% peanuts, then, [tex]\frac{x_{peanuts} }{x_{total} }[/tex] = 0.52.
Furthermore, 40% must be added.
[tex]x_{peanuts}[/tex] = [tex]0.4x[/tex] + [tex]11.16[/tex]
This gives us the following equation,
[tex]\frac{0.4x + 11.16}{18 + x } = 0.52[/tex]
Total mass =[tex]x + 18[/tex]
⇒ [tex]0.52 x +[/tex] 0.52 x 18 = [tex]0.4x + 11.16[/tex]
⇒ 0.12[tex]x[/tex] = (0.62 - 0.52 ) x 18
⇒ [tex]x[/tex] = 15 kg
Hence, 15 kg must be added.
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AP Stats work, really confused please help asap!! Thank you
Answer:
The points scored for each game are approximately normally distributed. The numbers distributed are in order of value from the least to greatest, making it easy to get the medium or mean.
Step-by-step explanation:
It is -24° tonight, but the weather reporter predicted it would be 16° warmer tomorrow.
What will the temperature be tomorrow?
Answer:
-8°
Step-by-step explanation:
-24+16=-8
Solve for the variable k
The equation m/k = x solved for k will be k = m / x.
What are variables?variable, in algebra, a symbol (usually a letter) that represents an unknown numerical value in an equation. Commonly used variables are x and y (real unknowns), z (complex unknowns), t (time), r (radius), and s (arc length).
There are two types of variables in math:
dependent independent variablesIn mathematics, a variable is an alphabet or term that represents an unknown number or an unknown value or an unknown quantity. Variables are used especially in algebraic expression or algebra. For example, x 9=. is a linear equation where x is a variable, where 9 and are constants.
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screenshot underneath
Simplify them
Answer =11
a= bc-3c-3b/6c
look at the screenshots for steps
i iam in 4th grade, i need to know 5×395=5×(400×-5)
11975 is value of multiplication .
What does multiplication mean in math?
Multiplication in mathematics is a technique for determining the sum of two or more numbers. It is a fundamental operation in mathematics that we perform frequently.When a single number is added up several times, it is said to be multiplied. A 5 multiplied by a 4 results in 20 (5 + 5 + 5 + 5). The number five was taken, and four additions were made. Due to this, multiplication is occasionally referred to as "times."5×395=5×(400×-5)
1975 = 5 * ( - 2000 )
1975 = - 10000
= 10000 + 1975
= 11975
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Pease help me this is dew tonight!
Answer:
-2v+2u+5
Step-by-step explanation:
Distribute the negative sign outside of the parentheses to the values within the parentheses (2v, -2u, and -5). This will give you -2v+2u+5. Let me know if you want a more detailed explanation, hope this helps
. If a number is decreased by 4 and divided by 6, the result is
8.What would be the result if 2 is subtracted from the number
and then it is divided by 5 ?
Answer:
10
Step-by-step explanation:
The number is 52. If you subtract 2 you get 50, then after dividing by 5 you get 10.
Solve the proportion.
I WILL USE CROSS MULTIPLICATION
[tex]63(4x) = 84(12) \\ 63(4x) = 1008 \\ \frac{63(4x)}{63} = \frac{1008}{63} \\ 4x = 16 \\ \frac{4x}{4} = \frac{16}{4} \\ x = 4[/tex]
ATTACHED IS THE SOLUTION
Yuto left his house at 10 a.m. to go for a bike ride. By the time Yuto’s sister Riko left their house, Yuto was already 5.25 miles along the path they both took. If Yuto’s average speed was 0.25 miles per minute and Riko’s average speed was 0.35 miles per minute, over what time period in minutes, t, starting from when Riko left the house, will Riko be behind her brother?
The time period that Riko would be behind is going to be the inequality 0 ≤ t < 52.5 minutes .
How to solve the inequalityHow to solve for the period t that Riko would be behind her brother
The question says that at the time he left the house, Yuto was 5.25 miles ahead of her.
The amount of miles that she would have gained on Yuto within this period would be 0.35 - 0.25 = 0.1 miles on Yuto
Therefore at every mile she would be closing in on 0.1 miles
For her to close the gap that is made here, it would be 5.25 / 0.1
= 52.5 minutes
Therefore we would say that The time that Riko would be behind is going to be 0 ≤ t < 52.5 minutes .
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asap !! 50 points!!!!!!!!
Which is bigger? Show your work WITHOUT EVALUATING.
A = 3^2/2^3
or
B = 9^4/4^6
please help, it doesn’t let me give 100 points :/
Answer:
B is bigger
Step-by-step explanation:
a) 3^2 / 2^3
3*3 / 2*2*2
9/8
b) 9^4 / 4^6
9*9*9*9/4*4*4*4*4
6561 / 4096
1.601807
Find the slope and write an equation of the line which passes through the points.
b
(−3, 9) and (−3, −5)
Answer:
Slope: 0
Equation : y = 9
Plsss mark as Brainliest
Slope:
-5-9/-3+3
=-14/0
= 0
Equation:
input gradient and pair of x and y valuesin y = mx +c
9= 0(-3)+c
9 = 0 +c
c = 9
input gradient and c:
y = 9
A shape is shown on the graph: A coordinate grid is shown from positive 8 to negative 8 on the x-axis and from positive 8 to negative 8 on the y-axis. A triangle is shown on ordered pair 2, negative 2 and 4, negative 2 and 2, negative 6. Which of the following is a reflection of the shape? (5 points) a A coordinate grid is shown from positive 8 to negative 8 on the x-axis and from positive 8 to negative 8 on the y-axis. A triangle is shown on ordered pair 2, 2 and 4, 2 and 2, 6. b A coordinate grid is shown from positive 8 to negative 8 on the x-axis and from positive 8 to negative 8 on the y-axis. A triangle is shown on ordered pair negative 2, negative 2 and negative 4, negative 2 and negative 4, negative 6. c A coordinate grid is shown from positive 8 to negative 8 on the axis and from positive 8 to negative 8 on the y-axis. A triangle is shown on ordered pair 2, 2 and 2, 4 and 6, 2. d A coordinate grid is shown from positive 8 to negative 8 on the axis and from positive 8 to negative 8 on the y-axis. A triangle is shown on ordered pair negative 2, negative 4 and negative 6, negative 4 and negative 6, negative 2.
The option which gives the reflection of the triangle (shape) with vertices, (2, -2), (4, -2), and (2, -6) is option a
a. A triangle is shown on ordered pair (2, 2), (4, 2), (2, 6)
What is a reflection transformation?A reflection transformation is one in which the line across which the object is reflected acts like a mirror, such that the points are swapped across the line of reflection.
The coordinates of the vertices of the triangle on the coordinate grid are;
(2, -2), (4, -2), and (2, -6)Required; The coordinates of a reflection of the shape (the triangle)
Solution; The coordinates of a point (x, y) following a reflection across the y–axis is (-x, y)
The vertices of the image of the triangle following a reflection across the y–axis are therefore;
(2, -2) → (-2, -2)(4, -2) → (-4, -2)(2, -6) → (-2, -6)A reflection of the point (x, y) across the x–axis gives the point (x, -y)
A reflection of the triangle across the x–axis therefore gives;
(2, -2) → (2, 2)(4, -2) → (4, 2)(2, -6) → (2, 6)A reflection of the point (x, y) across the line y = x, gives (y, x)
The vertices of the triangle following a reflection across the line y = x are therefore;
(2, -2) → (-2, 2)(4, -2) → (-2, 4)(2, -6) → (-6, 2)A reflection of the point (x, y) across the line y = -x, gives (-y, -x)
The vertices of the triangle following a reflection across the line y = -x are therefore;
(2, -2) → (2, -2)(4, -2) → (2, -4)(2, -6) → (6, -2)The coordinates of the triangle in the options are;
a) (2, 2), (4, 2), (2, 6)
b) (-2, -2), (-4, -2), (-4, -6)
c) (2, 2), (2, 4), (6, 2)
d) (-2, -4), (-6, -4), (-6, -2)
The correct option is therefore option a with points on the image of the triangle of (2, 2), (4, 2), (2, 6) which corresponds with the coordinates of the triangle following a reflection across the x–axis
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280 -8 (-14+x)
What’s the solution??
[tex]=280-8(-14)-8(x)\\=280+112-8x\\=392-8x[/tex]
Attached is the solution. be alert -8 multiplies everything in the brackets
Find the missing side length, x. (image)
The missing side of the triangle is 7.2 units
How to find the missing side of a triangle?ABC is a triangle.
AD bisects(cut into half) the angle ∠BAC.
Therefore,
AB / BD = AC / DC
Hence,
AB = 12
BD = x
AC = 20
DC = 12
Therefore,
12 / x = 20 / 12
cross multiply
12 × 12 = 20x
144 = 20x
divide both sides by 20
x = 144 / 20
Therefore,
x = 7.2 units.
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Choose the improper fraction that is equivalent to the mixed numbers 4 3/4
Answer:
d) 19/4
Step-by-step explanation:
Given mixed number,
→ 4 3/4
Now the improper fraction is,
→ 4 3/4
→ 19/4
Hence, option (d) is correct.
Ella buys a hat in Sweden for 50 SEK( Swedish Krona).
Find the VAT paid by Ella.
Answer:
12.5 SEK
Step-by-step explanation:
VAT percentage in Sweden is 25% so, 25% of 50 = 12.5
Please help and thanks!!! :))
n(x)=16-0.5;n(x)=48
please hope meeeeeeeeeeeeeee
The value of x is -64.
What is equation?An equation is a mathematical statement with an 'equal to' symbol between two expressions that have equal values.
For example, 3x + 5 = 15.
Given:
n(x)=16-0.5x;
n(x)=48
So, equation both
48=16-0.5x
Now, add 0.5 both sides
0.5x+48=16
Now, subtract 48 both sides
0.5x=-32
Divide both side by 0.5
x= -64
Hence, the value of x is -64.
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Determine the intercepts of the line.
Answer:
y=(0,-45)
x=(-10,0)
Step-by-step explanation:
What is the inverse function of d(x)=2x-4?
d-¹(x) = 1/2x+2
d-¹(x) =4x+2
d-¹(x) =4x-2
d-¹(x) =1/2x-2
Inverse function of expression is [tex]\frac{1}{2}[/tex]x + 2.
What is an inverse function?An inverse in mathematics is a function that "undoes" another function. In other words, if f(x) produces y, then y entered into the inverse of f produces x. An invertible function is one that has an inverse, and the inverse is represented by the symbol f1.
In the broadest sense, inverse functions are functions that "reverse" one another. The inverse, f 1 f-1 f1f, start superscript, minus, 1, end superscript, must take b to a, for instance, if f takes a to b.
Given Data
d(x) = 2x -4
Inverse function-
d⁻¹(x)
y = 2x-4
2x = y-4
x = [tex]\frac{y +4}{2}[/tex]
y = [tex]\frac{x+4}{2}[/tex]
y = [tex]\frac{1}{2}[/tex]x + 2
Inverse function of expression is [tex]\frac{1}{2}[/tex]x + 2.
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each year, students in an elementary school take a standardizzed math test at the end of the school year. for a class of fourth-graders, the average score was 55.1 with a standard deviation of 12.3. in the third grade, these same students had an average score of 61.7 with a standard deviation of 14.0. the correlation between the two sets of scores is r
Answer:
y = 0.835x + 3.58
Step-by-step explanation:
If −3+ n≤ 25, which inequality represents the possible range of values for 4n-12?
A) 4n-12≤ -100
B) 4n-12≤ 100
C) 4n-122-100
D) 4n-12≥100
The range is 4n - 12≤100.
The inequality is -3 + n≤25. From this, we can find the range of n.
n≤25 + 3
n≤28
Now we have to find the range of 4n - 12. For this, we have to ≤multiply both sides with 4 and then subtract it from 12, in the range of n.
That is;
4n≤ 28×4
4n - 12 ≤112 -12
4n - 12 ≤100
Therefore the range is 4n - 12≤ 100.
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please help i need this in an hour is it right or not
Answer:
c 6√5 - 4√5
Step-by-step explanation:
your answer is correct
Use the quadratic formula to solve: 3x² + 4x + 2 = 0.
What is the value of the discriminant?
What does this tell you about the solutions to the equation?
Answer:
[tex]x=-\frac{2}{3}+\frac{\sqrt{2}}{3}i\\\\x=-\frac{2}{3}-\frac{\sqrt{2}}{3}i[/tex]
Step-by-step explanation:
The Quadratic Formula gives us the roots of a quadratic and is defined as: [tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
The discriminant is the part in the square root which is: [tex]b^2-4ac[/tex]
if the discriminant of the quadratic is zero, then the quadratic only has one distinct zero with a multiplicity of 2.
To see why, let's plug in zero for the discriminant: [tex]x=\frac{-b\pm\sqrt{0}}{2a}[/tex]
The square root of zero is just going to be zero: [tex]x=\frac{-b\pm0}{2a}[/tex]
Adding or subtracting zero doesn't change the value: [tex]x=\frac{-b}{2a}[/tex]
As you can see here it doesn't matter if we take the positive or negative solution, we'll get one value.
If the discriminant of the quadratic is positive, then the quadratic will have two distinct real solutions.
Well the solutions are real because the square root has real solutions for positive numbers. The reason we have two distinct solutions is because the square root of a positive number will have a positive and negative solution. These square roots will have a non-zero value and will affect the value of the numerator based on whether you take the negative or positive solution giving you two distinct solutions.
If the discriminant of the quadratic is negative, then the quadratic will have two distinct complex solutions.
To clarify, real numbers are technically complex numbers, since complex numbers are just: [tex]a+bi[/tex], where a=real part, and b=imaginary part. We could use this to represent any real number where b=0.
So when I'm saying "complex solution" I mean a complex solution where b does not equal zero, so there is a non-zero imaginary component to the complex solution.
The reason we have a complex solution in the first place is because we have a negative number in the square root. The square root only has real solutions for positive numbers, since any real number squared will give you a positive number regardless of the sign (positive or negative). The only number that is negative when squared is an imaginary number.
The reason we have two distinct solutions is actually the same reason we have two distinct solutions when the discriminant is positive. Since the square root will yield a non-zero number, so when we add it or subtract it to b, we will get to different values for the numerator, giving us two different values, or two different solutions.
So now let's solve the equation: [tex]3x^2+4x+2=0[/tex]
We have it in standard form where: [tex]ax^2+bx+c=0[/tex]
we want to use the Quadratic Formula: [tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
Plugging in values we get:
[tex]a=3,\ b=4,\ c=2\\\\x=\frac{-4\pm\sqrt{4^2-4(3)(2)}}{2(3)}\\\\x=\frac{-4\pm\sqrt{16-24}}{6}\\\\x=\frac{-4\pm\sqrt{-8}}{6}[/tex]
From here you'll notice the discriminant is -8, and thus we complex solutions since it's negative. We can first break up this square root into multiple square roots using the fact that: [tex]\sqrt{ab}=\sqrt{a}*\sqrt{b}[/tex]
and since -8 can be defined as: -1 * 8, we can split it up like this
[tex]x=\frac{-4\pm\sqrt{-1}*\sqrt{8}}{6}\\\\x=\frac{-4\pm i\sqrt{8}}{6}[/tex]
We can actually simplify the square root a bit more, since we can once more use the identity: [tex]\sqrt{ab}=\sqrt{a}*\sqrt{b}[/tex], to simplify the radical. The number 8 can be represented as 4 * 2, and sqrt(4) can be simplified easily.
[tex]x=\frac{-4\pm i *\sqrt{4}*\sqrt{2}}{6}\\\\x=\frac{-4\pm 2i\sqrt{2}}{6}\\\\x=\frac{(-2 * 2)\pm2i\sqrt{2}}{(3*2)}\\\\x=\frac{-2\pm i\sqrt{2}}{3}[/tex]
Now let's take the positive and negative solution to get the two distinct complex solutions. You can start with either but I'll just do the positive first.
Positive Solution:
[tex]x=\frac{-2+ i\sqrt{2}}{3}[/tex]
You could leave it like this, but generally whenever we have a complex number we want it in the form: [tex]a+bi[/tex] where the real and imaginary part are separate, so we can just distribute the division of 3
Positive Solution Continued:
[tex]x=\frac{-2+ i\sqrt{2}}{3}\\\\x=\frac{-2}{3}+\frac{\sqrt{2}}{3}i[/tex]
I also moved the "i" outside the fraction, so it's a bit easier to see the value of "b"
Negative Solution:
[tex]x=\frac{-2-i\sqrt{2}}{3}\\\\x=\frac{-2}{3}-\frac{\sqrt{2}}{3}i[/tex]
Two car owners are in need of car repairs. Hazel will need to pay the mechanic $1 per minute for labor, plus $40 to cover the cost of new parts. Megan will need to pay $10 for parts and $4 per minute for labor. Depending on how long each repair takes, the two jobs might end up costing the same amount. How much time would that take?
Write a system of equations, graph them, and type the solution.
Answer: 10 minutes
Step-by-step explanation:
It would mean a lot if someone would help me with this! I will give brainliest! Thank you!!!
Select the graph that correctly represents the following equation.
2 x − y = 1
Answer:
C
Step-by-step explanation:
Its c im smart trust me
Answer: C
Step-by-step explanation:
2x - y = 1
-2x -2x
-y = -2x + 1
(-1) -y = -2x + 1 (1)
y = 2x-1
slope is positive 2/1, and the y-intercept is -1
I only need the answer for 18 please
The equation of the line parallel to 2x + 3y = 18 and passing through point ( 6, 4) is 3y + 2x = 24.
Consider the line 2x + 3y = 18,
The equation of the line in slope-intercept form can be written in the form y = mx + b, where m is the slope of the line.
Therefore,
2x + 3y = 18
Subtracting 2x from each side
2x + 3y - 2x = 18 - 2x
3y = 18 - 2x
Dividing each side by 3.
y = 6 - ( 2/3 )x
y = - (2/3)x + 6
Hence, the slope of the line is - 2/3.
Now, if two lines are parallel then they have the same slope.
Now, the line parallel to 2x + 3y = 18 passes through ( 6,4).
Therefore, using the slope-intercept form:
y = mx + b
4 = ( -2/3 ) × 6 + b
4 = - 4 + b
b = 8
Therefore, the equation of the line parallel to 2x + 3y = 18 is:
y = ( - 2/3 )x + 8
3y = - 2x + 24
3y + 2x = 24
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