Answer:
How does the number trick work?
Trick 1: Think of a number
Pick a whole number between 1 and 10.
Add 2.
Multiply by 2.
Subtract 2.
Divide by 2.
Subtract your original number.
Everyone's final answer will be 1.
Step-by-step explanation:
The Number 5 Trick. Ask somebody to think of a number and keep it secret. Then ask that person to double the secret number and then multiply by 5. Ask for the total. Whatever the total is, knock off the last digit and you will have the secret number the person mentally chose at the start.
LEMMEBE HONEST
I HAVE NO IDEAAAA
“Think-of-a-number” tricks
These tricks come in two types: Think of a number (but don't tell me), do some arithmetic with that number, and I can predict your result. Think of a number, do some arithmetic, tell me your result, and I can instantly say what number you started with.
Hope this helps!
Sending U good luck!
What is the best estimate of the measure of the angle shown?
*answer was incorrect please see below*
A circle is inscribed with 5 lines. The center of the circle is labeled point O. Four lines extend from point O. One connects to point W on the edge of the circle. The second line extends past the circle edge through point X on the edge. The third extends past the circle edge through point Z. The fourth extends past the circle edge through point Y. A line connects points W and X. The angle created by ray OX and ray OZ is angle . The two rays that create YOX are ray OX and ray . The center of the circle is point .
Answer:
XOZ
OY
O
Step-by-step explanation:
just took it on edge
PlS HELP QUICKLY :One of the roots of the equation x2−bx+c=0 is equal to 5. Find c in terms of b.:
Guys pls help and find what C is equal to.
Answer:First suppose that the roots of the equation
x2−bx+c=0(1)
are real and positive. From the quadratic formula, we see that the roots of (1) are of the form
b±b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√2.
For the root or roots to be real, we require that b2−4c≥0, that is, b2≥4c. In order for them to be positive, we require that
b−b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√>0.
This immediately tells us that b>0, but we can go further. We can rearrange this to get
b>b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√,
which (assuming that b>0) is true if and only if
b2>b2−4c,
since both sides of the inequality are positive so we may square. But then
4c>0.
That is, if the roots are real and positive then b>0 and b2≥4c>0.
Now suppose that b>0 and b2≥4c>0.
Then the roots of (1) are real since b2−4c≥0, and b>0 guarantees that the root b+b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√ is positive.
So it remains to show that b−b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√>0. We have that
4c>0,
so that
b2>b2−4c,
then square rooting shows that
b>b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√,
so the roots of (1) are real and positive, as required.
Approach 2
the curve y equals x squared minus b x plus c showing two positive roots for y equals zero
This is intended to be a proof without words! We have from the diagram that:
If c, b and b2−4c are all positive, there are two real positive roots for x2−bx+c=0 (if b2=4c, we have two real positive equal roots).
If there are two real positive roots for x2−bx+c=0, then c and b are positive and b2−4c is non-negative.
(Why is the distance between the roots b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√?)
Approach 3
When solving problems about the roots of polynomials, it is often useful to find expressions those roots must satisfy and see if this tells us anything new. If α and β denote the roots of the equation, then
x2−bx+c=(x−α)(x−β)=x2−(α+β)x+αβ
and so α+β=b and αβ=c.
We also know that the roots of a quadratic equation are real if and only if the discriminant is non-negative, that is, if and only if b2−4c≥0.
Using these facts, if α and β are both real and positive, then b=α+β>0, c=αβ>0 and b2≥4c, as above.
Conversely, if b>0 and b2≥4c>0, then we know the discriminant is positive and hence both roots are real. We also have that
αβ>0(2)
and
α+β>0.(3)
As α and β are both real, by (2), we know that α and β are either both positive or both negative. However, if α and β were both negative, then (3) could not possibly hold. Hence α and β are both positive, as required.
We now sketch on a graph the region where b>0, c>0 and b2≥4c:
The curve b squared = 4 c as a quadratic with the c-axis vertical and the b-axis horizontal. The region below it is shaded.
The region of the b-c plane for which b>0, c>0 and b2≥4c
Sketch the region of the b-c plane in which the roots of the equation are real and less than 1 in magnitude.
We know that in order for the roots to be real we need b2≥4c as in the first part. We now need to find the region where
−1<b±b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√2<1.(4)
We have b−b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√2≤b+b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√2 so we only need to consider the values for which both
−1<b−b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√2andb+b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√2<1.
Firstly, we will consider the values for which
b+b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√<2.
Rearranging gives
b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√<2−b.
So b<2, as the square root is non-negative, and we can square both sides to get
b2−4c<4−4b+b2,
which we may rearrange to find c>b−1.
We will now consider the values for which
−2<b−b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√.
Similarly, we can rearrange to get
b2−4c⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√<b+2.
So b>−2, and we can, as before, square to get
b2−4c<b2+4b+4,
and hence c>−b−1.
To sketch the graph, we start by considering the boundary curves b2=4c, c=b−1 and c=−b−1, and the points at which they intersect. We can see that the two lines only intersect when b=0 and c=−1, and the lines intersect the curve when
b2=4b−4andb2=−4b−4
which rearrange to
(b−2)2=0and(b+2)2=0.
This tells us that each line intersects with the curve in only one place and so these lines must be tangent.
Is there a way we could have deduced this directly from (4)?
What do the lines being tangent signify in terms of our equation x2−bx+c=0?
Is this a representation of a well-known property of these equations?
Sketching the graph then yields the following picture:
The graph with the previous curve and the lines 4 c = 4 b minus 4 and 4 c = minus 4 b - 4. Each line touches the curve once and the two lines intersect at (0, minus 1). The region between the three lines/curves is shaded.
The shaded region is where b2≥4c, c>b−1, c>−b−1 and −2<b<2
We might notice that when we derived the inequalities c>b−1 and c>−b−1, a lot of the work we did was very similar.
We might also notice that the graph above is symmetric about the c axis. Why is this?
Does the graph give us any ideas about how we might deduce one inequality from the other?
Step-by-step explanation:
write in the simplest form 5.73 - ( -3.56)
Answer:
9.28
Step-by-step explanation:
PLEASE HELP FAST
The midpoint of AB is M(-4, 0). If the coordinates of A are (-6, 6), what are the coordinates of B?
Answer:
The coordinates of B are: (a, b)=(-2, -6)
Step-by-step explanation:
Let (a, b) be the coordinates of the point 'B'.
As
The midpoint of AB is M(-4, 0)
The coordinates of A are (-6, 6)
The midpoint (x,y) of line joining points (x₁, x₂) and (y₁, y₂)
[tex]x=\frac{x_1+x_2}{2},\:y=\frac{y_1+y_2}{2}[/tex]
-4 = (-6+a)/2 and 0 = (6+b)/2
-8=-6+a
-8+6=a
a=-2
0=(6+b)/2
0=6+b
b=-6
Therefore, the coordinates of B are: (a, b)=(-2, -6)
Simplify the expression by adding or subtracting the linear expressions. 12x + 6 - 8x + 7 *
4x + 1
4x + 13
20x + 13
20x + 1
Answer:
4x+13
Step-by-step explanation:
bc 12-8=4
6+7÷13
1/4 of a pizza was broccoli and half was mushroom and 1/4 was three cheeses. George ate 1/3 of the broccoli part and 1/3 of the mushroom part and 1/2 of the 3 cheese part. How much of the total pizza did he eat?
Write the equation of the line through the given points (3, 5) and (-3,-3) in the three different forms.
Point-Slope Form
Slope-Intercept Form
Standard Form
Answer:
y-5=1/3(x-3)
y=1/3x+4
no standard form
Step-by-step explanation:
yk = m + n
Solve the following equation for k:
Julie buys a new shirt. The original price of the shirt is $35.00, but it is on sale for 25% off. There is a 7% tax on the shirt. How much will Julie pay for the shirt?
Answer: $24.08
Step-by-step explanation: 25% off $35.00 is $22.50
and adding 7% tax which equals $1.50
so it adds up to 24.08
Gumballs cost $0.50 each and jawbreakers cost 0.30 each bob has $3.00 to spend
Create an inequality that represents the number of gumballs and jawbreakers Bob can buy
Answer:
a0.50 + b0.30 ≤ $3.00
Step-by-step explanation:
From the question, we have:
Gumballs cost per unit = $0.50
Jawbreakers cost = $0.30
Total budget of Bob = $3.00
Let a represents the number of Gumballs Bob can buy.
Let b represents the number of jawbreakers Bob can buy.
Therefore, inequality that represents the number of gumballs and jawbreakers Bob can buy can be given as follows:
a0.50 + b0.30 ≤ $3.00
The inequality implies that total amount Bob can spend on both gumballs and jawbreakers can be less or equal to $3.00 but cannot be greater than $3.00.
Infer Jamal is in a car going north. He looks out his window and thinks that the northbound traffic is moving very slowly. Ellen is in a car going
south. She thinks the northbound traffic is moving quickly. Explain why Jamal and Ellen have different ideas about the motion of the traffic.
Answer:
relax jamal dont pull up the 9
Step-by-step explanation:
the polygon is regular if each of its side has the same length. find the perimeter of the regular polygon.
18, 19, 20
helpp!!!!
if it takes 16 yards of material to make costumes, how much material will be needed to make costumes of that same size?
A.
60.8 yards
B.
50.7 yards
C.
40 yards
D.
34 yards
Answer:
Need more information, will get back to you.
Step-by-step explanation:
How many costumes does she want to make?
A number is called flippy if its digits alternate between two distinct digits. For example, 2020 and 37373 are flippy, but 3883 and 123123 are not. How many five-digit flippy numbers are divisible by 15?
A 3
B 4
C 5
D 6
E 8
Answer: B: 4
Step-by-step explanation:
A number is divisible by 15 if the number ends on a 0 or a 5, and the sum of its digits is divisible by 3.
We want to find a 5 digit flippy number, this can be: modeled with:
N = ababa
Where a and b are single digit numbers.
If we impose that N must end with a zero, then we will have:
N = 0b0b0 = b0b0
This is a 4-digit number, so we can discard all the options that end with a zero.
Then the only option that we have are the numbers like:
B = 5b5b5
This number will be only divisible by 15 if:
5 + b + 5 + b + 5 = K is divisible by 3.
Then let's try find the possible values of b.
K = 3*5 + 2*b
K has two terms, the left term is already divisible by 3, then K will be divisible by 3 only if the other term is also divisible by 3.
Then we want 2*b to be divisible by 3.
And 2 is a prime number, then b must be divisible by 3, and we know that b is a number between {0,1 , 2, 3, 4, 5, 6, 7, 8 ,9}
The options are:
2*0 = 0 is divisible by 3.
2*3 = 6 is divisible by 3.
2*6 = 12 is divisible by 3
2*9 = 12 is divisible by 3.
Then we have four values of b such that:
N = 5b5b5 is divisible by 15.
Then the correct option is: B: 4
What is the nature of the solution set to the following system of equations?
5x - y = 2
2x-0.5y=3
Answer:
u can use substitute or eliminate
Graph the equation on the coordinate plane y=-3/2x -4
Answer:
The 3, and -4 are the places where you start, then just graph 1/2 and -3 as slope
Step-by-step explanation:
Step-by-step explanation:
you start at -4 and then you go down 3 and to the right 2
Can someone please help me with this? It’s the last problem I need to turn in a test, I will mark brainliest :(
Answer:
33b - 8
Step-by-step explanation:
You solve for the perimeter like you would for any other shape by adding all the sides
The perimeter is side A + side B + side C.
so it's 9b+8 + 12b-8 + 12b-8
Add all the like terms
9b + 12 b + 12b = 33b
8 - 8 - 8= -8
= 33b -8
what is 20*5 yay plz help me anwer this
Answer: 100. Can I get a Brainlest.
100 is the answer
Multiply.....
God Bless
The function h(n) gives the number of person-hours it takes to assemble n engines in a factory. What is a reasonable domain for h(n)?
Answer:
For example, if the function h(n) gives the number of person-hours it takes to assemble n engines in a factory, then the positive integers would be an appropriate domain for the function.
BRAINLIEST TO WHOEVER ANSWERS FIRST!!
Which two statements, if true guarantee that is congruent to B?
Choose 2 answers
FGBF
DHBF
HIDH
HI FG
Answer:
HI FG
Step-by-step explanation:
The polygons to the right are similar. Find the values of each variable! ( simplify ur answer)
Help mee please i have a headache
Answer:
hi! i'm so sorry about your headache, hope it gets better !
still need help?
Step-by-step explanation:
pleaseeeee helpppppp
Answer:
BCE
Step-by-step explanation:
I hoped this helped and mark me as brainly pls
Answer:
a c b d
Step-by-step explanation:
The chances that a student will get 7 marks out of 10 in first attempt of a certain Quiz while attempting Quiz on BlackBoard LMS is 40%. Suppose that 20 students are selected at random then find a probability that i)Exactly 12 students will get 7 marks out 10 in the Quiz. ii)Fewer than 10 students will get 7 marks out 10 in the Quiz. iii)At least 5 students will get 7 marks out 10 in the Quiz.
Answer:
i) [tex]P(X=12)=0.0355[/tex]
ii) [tex]P(X<10)=0.7553[/tex]
iii) [tex]P(X\geq 5)=0.9490[/tex]
Step-by-step explanation:
Let's start by defining the random variable ⇒
[tex]X:[/tex] '' Number of students that will get 7 marks out of 10 in first attempt of a certain Quiz while attempting Quiz on BlackBoard LMS ''
[tex]X[/tex] is a discrete random variable.
The probability of a randomly selected student getting 7 marks out of 10 is 0.4
(This is a data from the question).
Now, if we assume independence between the students while they are doing the Quiz and also we assume that this probability remains constant , we can modelate [tex]X[/tex] as a binomial random variable ⇒
[tex]X[/tex] ~ Bi (n,p)
Where ''n'' and ''p'' are the parameters of the variable.
''n'' is the number of students attempting the Quiz and ''p'' is the probability that a student will get 7 marks out of 10 which is 0.4 ⇒
[tex]X[/tex] ~ Bi (20, 0.4) in the question.
The probability function for [tex]X[/tex] is
[tex]p_{X}(x)=P(X=x)=\left(\begin{array}{c}n&x\end{array}\right)p^{x}(1-p)^{n-x}[/tex] (I)
Where [tex]\left(\begin{array}{c}n&x\end{array}\right)[/tex] is the combinatorial number define as
[tex]\left(\begin{array}{c}n&x\end{array}\right)=\frac{n!}{x!(n-x)!}[/tex]
Replacing the parameters in the equation (I) ⇒
[tex]P(X=x)=\left(\begin{array}{c}20&x\end{array}\right)(0.4)^{x}(0.6)^{20-x}[/tex] (II)
For i) we need to find [tex]P(X=12)[/tex]
Then, we only need to replace by [tex]x=12[/tex] in equation (II) ⇒
[tex]P(X=12)=\left(\begin{array}{c}20&12\end{array}\right)(0.4)^{12}(0.6)^{8}=0.0355[/tex]
For ii) we need to calculate [tex]P(X<10)[/tex]
This probability is equal to ⇒ [tex]P(X<10)=P(X\leq 9)[/tex] and to calculate it we need to sum [tex]P(X=0)+P(X=1)+P(X=2)+P(X=3)+P(X=4)+P(X=5)[/tex]
[tex]+P(X=6)+P(X=7)+P(X=8)+P(X=9)[/tex]
We can do it summing each term or either using any program.
The result is [tex]P(X<10)=P(X\leq 9)=0.7553[/tex]
Finally for iii) we need to find ⇒ [tex]P(X\geq 5)[/tex]
This probability is equal to ⇒ [tex]P(X\geq 5)=1-P(X\leq 4)[/tex] ⇒
[tex]1-P(X\leq 4)=1-[P(X=0)+P(X=1)+P(X=2)+P(X=3)+P(X=4)][/tex]
Again we can find each term by using the equation (II) or either using a program. The result is [tex]P(X\geq 5)=0.9490[/tex]
what is the percent of change between 57000 people and 97000 people, and how do I solve it?
Answer:
58.76
Step-by-step explanation:
So, as you can tell 97,000 is the 100 percent of the people, in this case we don't know what 57,000 is. Just divide equation 1 by equation 2. Considering both have the same unit. I'm so sorry, if this doesn't explain the best way.
El entrenamiento que hace marco 10 dias antes de su carrera es constante. Diariamente corre 45 minutos a una velocidad de 30 km-h ¿Cuántos kilómetros ha corrido Marcos durante esos 10 dias?
Responder:
225 kilometros
Explicación paso a paso:
Dado que :
Velocidad de funcionamiento = 30 km / h
Duración = 45 minutos
Número de días = 10 días
Distancia total recorrida por día:
Duración en horas:
45 minutos / 60 = 0,75 hora (s)
Así, la distancia recorrida por día:
Tiempo de velocidad
30 km / h * 0,75 h = 22,5 km
Por lo tanto, la distancia total recorrida durante 10 días:
Distancia recorrida diariamente * 10
22,5 kilometros * 10 = 225 kilometros
Triangle CDA is the image of triangle ABC after a 1800 rotation around the midpoint of segment AC. Triangle ECB is the image of triangle ABC after a 1800 rotation around the midpoint of segment BC.
Explain why ABCD and ABEC are parallelograms.
Identify at least two pairs of congruent angles in the figure and explain how you know they are congruent.
Explain how to use what you know about the sum of the angles in a triangle to figure out the sum of the angles of quadrilateral ABED.
1. they both have 2 different congruent sides
2. angles ACD and BEC, since they are the same triangles, and are at congruent ends
3. since they are all the same triangle and has just been rotated some, you can figure out that it is the same triangle. once you figure out the angles for one of the triangles, you can figure outit for the other 2 since they are all congruent.
i hope this helped :)
Is correct that is rounded to 30 BRAINLY PLS HELP ME OUT I FORGIT HOW TO DO THIS ASP !PLS !
Answer:
No, it doesn't.
Step-by-step explanation:
Whenever there's a "th" at the end of a mathematical word, it means decimal place. A tenth is the first number in a decimal. Ex. (Underlined is the tenth) 1.27. If you round them to the tenth, you would get 20 and 30. Therefore 20 does not round to 30 if rounding to the tenths.
Answer:
It would actually be 20.
Step-by-step explanation:
When rounding to the nearest tenth, you need to pay attention to the second-to-last digit in the number. If the number is anything from 0 - 4 it rounds down. If the number is anything from 5 - 9, it rounds up.
Feel free to give brainliest.
Have an excellent day!
[tex]\sqrt{8}+\sqrt{18}-\sqrt{32}[/tex]
WILL GIVE BRAINLIEST. Will report if answer is absurd What is the trademark of a linear table?
Answer:
You can tell if a table is linear by looking at how X and Y change. If, as X increases by 1, Y increases by a constant rate, then a table is linear. You can find the constant rate by finding the first difference.
Step-by-step explanation:
Hope this helps!