Answer:
When you multiply a negative by a negative you get a positive, because the negative signs cancel each other.
y = 4x + x Convert to standard form
Answer:
5x-y=0
Step-by-step explanation:
The half-life of a substance is the amount of time it takes for half of the amount of substance to decay. The half-life of a pesticide is 2 years. Initially there are 500 grams of pesticide. How much pesticide is left after 10 years? Round to the nearest hundredth.
Answer:
15.625 grams
Step-by-step explanation:
The decay is First order reaction
The half life of the first order reaction is given by
T(1/2) = ㏑2/K
where K is the reaction constant for the first order reaction
T(1/2) = 2
2 = ln 2 /K
K = ln2/2
The equation of the first order reaction is given by
Kt = ln ([tex]\frac{Ro}{R}[/tex])
where
t = time = 10years
Ro = initial concentration
R = amount left after time t
upon substituting the values
[tex]\frac{ln2}{2}*10 = ln( \frac{500}{R})[/tex]
5ln2 = ln (500/R)
ln [tex]2^5[/tex] = ln (500/R) (a*lnb = ln[tex]b^a[/tex])
[tex]2^5 = 500/R[/tex]
R = 500/32 = 15.625grams
Therefore the amount of pesticide left after 10 years is 15.625grams
Help me please find the equation of the line
Answer:
y= [tex]\frac{-1}{24}[/tex]x - [tex]\frac{3}{4}[/tex]
Step-by-step explanation:
(4,-1),(6,1): two points
-1(1)/4(6): find slope
slope: [tex]\frac{-1}{24}[/tex]
write in point-slope form: y+1=[tex]\frac{-1}{24}[/tex](x-6)
y= [tex]\frac{-1}{24}[/tex]x - [tex]\frac{3}{4}[/tex]
i will give brainilist to the first person who wants to do my delta math
y2 – x2 = 16 please help
Jasmine and Scott want to chart their reading rates to see how much they improve each quarter. Below are the results of their first quarter tests. Write their results as unit rates. Jasmine can read 120 words per minute. 2. It takes Scott one minute to read 130 words.
Answer:
a) 120 words per minute
b) 130 words per minute
Step-by-step explanation:
A unit rate (also called a single-unit rate) is a type of ratio that compares 1 unit of one quantity to a different number of units of a another different quantity. When expressing in unit rate, the second quantity is in one unit.
a) Jasmine can read 120 words per minute
Jasmine reading unit rate = total number of words read / time taken
Jasmine reading unit rate = 120 words / 1 minute = 120 words per minute
b) It takes Scott one minute to read 130 words
Scott reading unit rate = total number of words read / time taken
Scott reading unit rate = 130 words / 1 minute = 130 words per minute
Does anyone understand this?
Answer:
C
Step-by-step explanation:
Solve 2x>8 or 2x< 4.
Answer:
2x=8
x=8/2
x=4
2x=4
x=4/2
x=2
Sofia exchanged 1,000 US dollars for the currency of South Africa, which is called the rand. The exchange rate was 7.45 rand to $ 1.
Part 1 of 2
How many South African rand did Sofia get? Explain how you know.
For every $ 1 that Sofia exchanges,____ she received _____
rand. So, you multiplied $ 1,000 ×______=?
. Sofia got _____
rand.
Gerald wants to buy a pair of jeans, polyester pants, or cotton pants for his upcoming camping trip. The cost is similar for each item, and he can't decide which to buy. So, he plans to make a random selection. Which model can Gerald choose to simulate this situation, and what is the probability of picking a pair of jeans using this model?
A.
He can use a random number generator with the numbers 1 to 10. The probability is .
B.
He can choose one of three playing cards. The probability is .
C.
He can flip a coin. The probability is 3.
D.
He can flip a bottle cap. The probability is 1.
Answer:
B
Step-by-step explanation:
certain types of playing cards are cheap if you buy the right one then you'll have more money
change 5 out of 19 to one decimal place
change 72 out of 123 to one decimal place
Answer:
6
Step-by-step explanation:
What is an equation of the line that passes through the point (-8,0) and is
parallel to the line x + 2y = 14?
Answer: y = -1/2x -4
Step-by-step explanation:
Parallel lines have the same slope.
So first let’s find the slope of that given line.
x + 2y = 14
2y = -x+14
y = -1/2x + 7
The slope of our parallel line then will be -1/2.
Now let’s use the point they gave us to get “b” so we can finish the problem.
y= -1/2x + b
plug in (-8,0) so -8 for x and 0 for y
0 = -1/2(-8) + b
0 = 4 + b
b = -4
done!
An equation of the line that passes through the point (-8,0) and is
parallel to the line x + 2y = 14 is 2
Equation of a lineThe equation of a line in point slope form is expressed as:
y - y1 = m(x-x1)m is the slope(x1 y1) is the point on the lineGiven the equation
x + 2y = 14
2y = -x + 14
y = -1/2x + 7
Slope of the line is -1/2
Substitute the point (-8, 0) and m = -1/2 into the formula
y - 0 = -1/2 (x+8)
2y = -x - 8
2y + x = -8
Hence an equation of the line that passes through the point (-8,0) and is
parallel to the line x + 2y = 14 is 2y+ x = -8
Learn more on equation of a line here: https://brainly.com/question/19417700
(30 points!) Powers of i worksheet
Answer:
x+7=14
x=7
(7)+7=14
Step-by-step explanation:
Help asap please!! I will mark you as brainliest :)
Answer:
52
Step-by-step explanation:
bro imma be honest with you the way i figured this out doesnt even make sense so im not even gonna try and explain ths lol
Mrs. King has a stack of papers to grade that contains 12 boy's papers and 8 girl's papers. What is the probability that the first paper Mrs. King's grades will be a boy's paper? *
!!!!Hurryy plz will give 20 points and brainlyest plzzzzzz!!!
Which division problem does the model show?
Answer:
B
Step-by-step explanation:
Answer:
b
Step-by-step explanation:
50.2 x 1 10² tenths equal?
Answer:
607,420
Step-by-step explanation:
hope it is correct and helps
f(x) = x-1 + 2x + 12x3
=12
X-1+2x+12*3
re-arrange
X+2x=36+1
3x=37
X=37/3
X=12.3333
approximately
X=12
F(X)
=F(12)
hope it useful
Which section of the function is constant? (2 points)
1) A
2) B
3) C
4) D
Solve: x^2-x-6=0
Show your wrok
or
x=3The factors of which -6 which sum to -1 are -3 and +2(x-3) (x+2)=2Equate each factor to zero and solve for xx +2=0→x=-2x-3=0→x=3.State the slope and the y-intercept for the graph of the equation. -x+y=4
Answer:Step-by-step explanation:
slope is 1
y intercept is 4
equation y= 1x+4
i like to ride on the interurban trail for a total distance of 30 miles. it takes me 2 hours. what is my average speed while riding my bike in miles per hour?
Answer:
15mph
Step-by-step explanation:
So to figure this out you have to get the total unit rate by dividing 30 and 2 which in total gives you 15
So congratulations you can ride 15 miles per hour :)
Answer:15 mph
Step-by-step explanation:
Felicia had $80 when she went to a music store that charges $18 for each CD. She needs to have no less than $20 in her wallet when she leaves the store so she has enough money to buy gas for the ride home. Which shows a possible number of CDs she could buy?
Answer: See explanation
Step-by-step explanation:
Let the possible number of CDs that she could buy be represented by x. Then, the equation can be represented as:
80 - 18x ≤ 20
80 - 20 ≤ 18x
60 ≤ 18x
x ≤ 60/18
x ≤ 3.33
The highest amount of cd that she can is 3 or less.
helphelp need lots of help. do atleast one idc need hELP
Answer:
31. $70 / 34. 9.5, 9, or 10.
Step-by-step explanation:
31. ok here it looks like they split the cost between each other. if im correct, that means they split the thing in 5. which means Tai is paying for [tex]\frac{2}{5}[/tex] the of the camera. [tex]\frac{1}{5}[/tex] of the total cost of the camera is 35, so 35 x 2 = 70. Tai is paying $70.00
im not good with liters and things like that with ratio, sorry about that
34. ok so the long side of the rectangle is 18 cm, and this has a ratio of 5 : 3. so for every 5 cm the small side is 3 cm. so if something was 18 cm, it would make the shorter side 9.5 or if it only requires whole numbers then either 9 or 10.
i hope this helped, i did my best :)
find the slope of the line through each pair of points ( -5, 10) , (-16, 8)
Answer:
-2/-11 or 2/11
Step-by-step explanation:
8-10=-2
-16--5=-11
-2/-11
The circumefreence of a circle is 37.8. What is the area of the circle? Use 3.14 for pie
Answer:
b
Step-by-step explanation:
circumference= 2πr
37.8cm = 2πr
r= 6 cm
Area= πr^2
area = 113cm^2
Johnathon weight 60 pounds when he was in the 4th grade. Over the last four years, he has gained 80% of his original weight. How much does he weigh now? A. 140 pounds
B. 108 pounds
C. 120 pounds
D. 131 pounds
Answer:
108
Step-by-step explanation:
60 plus 80% = 108
Answer:b
Step-by-step explanation:108 60x80
Solve the proportion:
Answer:
15
Step-by-step explanation:
Answer:
x = 15
Step-by-step explanation:
cross multiply
9*10=90
90/6=15
The scatter plot shows a regression line of advertising dollars spent and sales. What advertising dollar has the greatest error term?
A) $250,000
B) $262,500
C) $275,000
D) $337,500
Answer:c
Step-by-step explanation:
The coordinate grid below shows triangle ABC and its image after translation, triangle A'B'C': BY C' 7 B 6 2 A 3= + 2 -7-6-5-4-3-2-1 Which of the following completes the rule for this translation, (x, y) = (x - 8, points) ? (4 O y-6 Oy-3 O y + 6 O'y+3
need help asap please
Answer: y+3
Step-by-step explanation: I'm taking the test rn
Answer:
y + 3
Step-by-step explanation:
I took the test and got it right.