If x+y=15 and x-y=25, then what is the value of 2x^2 - y^2?

Answer:

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[tex]36x^3,\:22x^2,\:4xy[/tex]

Factor 36x³

Factor 22x²

Factor 4xy

Common factor

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[tex]36x^3-22x^2-12x[/tex]

Factor 36x³

Factor 22x²

Factor 12x

Common factor

OAmalOHopeO

Answer:

3.5 cm

Step-by-step explanation:

v = πr²h

r = radius

π = 22/7

h = height

192.5 = 22/7 x 5 x r²

divide both sides of the equation by (7/22 x 1/5)

192.5 x 7/22 x 1/5 = r²

r² = 12.25

find the square root of both sides

r = 3.5cm

Answer:

rational, simplified number is -0.5

Step-by-step explanation:

(see screenshot)

Answer:

2

y = 3x-15

y=5x-35

x1=5

x2=7

distance between = 7-5 = 2

Step-by-step explanation:

Answer:

1. -18x+6

multiply everything inside with the number outside the bracket

2. -18x-6

same as number one

3. 18x-12

same as number one

4. -18x-6

same as number one

for 5 I can't see it well but it should be similar

you just need to substitute what's outside the bracket to what Is inside the bracket

Answer: -6 (3x+1)

Step-by-step explanation:

Factor the polynomial -18x-6−18x−6 by it's GCF: -6−6

Answer:

A ≈ 21.22 m²

Step-by-step explanation:

The area (A) of a triangle using Heron's formula is

A = [tex]\sqrt{s(s-a)(s-b)(s-c)}[/tex]

where s is the semi perimeter and a, b, c the sides of the triangle.

Here the perimeter of the equilateral triangle is 21 m , then

a = b = c = 21 ÷ 3 = 7 m

s = 21 ÷ 2 = 10.5

Then

A = [tex]\sqrt{10.5(10.5-7)(10.5-7)(10.5-7)}[/tex]

   = [tex]\sqrt{10.5(3.5)(3.5)(3.5)}[/tex]

   = [tex]\sqrt{450.1875}[/tex]

   ≈ 21.22 m² ( to 2 dec. places )

Answer:

B

Step-by-step explanation:

The average rate of change of f(x) in the closed interval [ a, b ] is

[tex]\frac{f(b)-f(a)}{b-a}[/tex]

Here [ a, b ] = [ 1, 3 ] , then

f(3) = 18 ← value of y when x = 3

f(1) = 2 ← value of y when x = 1

Then

average rate of change = [tex]\frac{18-2}{3-1}[/tex] = [tex]\frac{16}{2}[/tex] = 8 → B

Answer:

140

Step-by-step explanation:

Lowest common denominator 4 , 7 ,5 , 2  and 1

= 4 * 7 * 5

= 140

Answer:

1

Step-by-step explanation:

Since usually common denominator is usually used with fractions (in this case), we can find out it's one because of how no numbers (except for 2 and 4) go into each other without a remainder except for one, so one would be the correct answer

Answer:

-2/25

Step-by-step explanation:

Use the slope formula: rise/run to find the slope

Answer:

slope = - [tex]\frac{2}{25}[/tex]

Step-by-step explanation:

Calculate the slope m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (- 20, 18) and (x₂, y₂ ) = (30, 14)

m = [tex]\frac{14-18}{30-(-20)}[/tex] = [tex]\frac{-4}{30+20}[/tex] = [tex]\frac{-4}{50}[/tex] = - [tex]\frac{2}{25}[/tex]

Answer:

The correct answer is - A.(112.86, 127.14)

Step-by-step explanation:

Given:

mean = $120

sd = $17.50

n = 40

Solution:

Confidence interval for a populationcan be express as mean +/- margin of error (E)

degree of freedom = n-1 = 40-1 = 39

confidence level (C) = 99% = 0.01

significance level = 1 - C = 1 - 0.01 = 0.99 = 99%

 by margin of error E = t×sd/√n = 2.58*17.50/√40

= 2.58*2.76

= 7.138 or 7.14

then the lower limit of mean = mean - E = 120 - 7.14 = $112.86

and, the upper limit of population mean = mean + E = 120 + 7.14 = $127.14

Answer:

[tex]P = 0.1447[/tex]

Step-by-step explanation:

Given

[tex]n = 7000[/tex] -- total

[tex]d = 180[/tex] --- defective

[tex]r = 6[/tex] --- selected

Required

The probability of rejecting the batch

This means that at least one of the selected piece is defected.

So, we first calculate the probability that all the selected piece are accepted.

So, we have:

[tex]Pr = \frac{7000 - 180}{7000} * \frac{6999 - 180}{6999}* \frac{6998 - 180}{6998}* \frac{6997 - 180}{6997}* \frac{6996 - 180}{6996}* \frac{6995 - 180}{6995}[/tex]

The denominator decreases by 1 because it is a probability without replacement; 180 is subtracted from the numerator to represent the number of non-defective CDs

So, we have:

[tex]Pr = \frac{6820}{7000} * \frac{6819}{6999}* \frac{6818}{6998}* \frac{6817}{6997}* \frac{6816}{6996}* \frac{6815}{6995}[/tex]

[tex]Pr = 0.8553[/tex]

Using the complement rule, the probability that the batch will be rejected is:

[tex]P = 1 - 0.8553[/tex]

[tex]P = 0.1447[/tex]

Answer:

D

Step-by-step explanation:

The median goes from the vertex to the midpoint of the opposite side, so

LN = NM , that is

3x - 7 = 5 ( add 7 to both sides )

3x = 12 ( divide both sides by 3 )

x = 4

Then

KL = 2x + 3 = 2(4) + 3 = 8 + 3 = 11 → D

Answer:

Similarity: Both graphs have same y-intercepts.

Difference: Graph 2x + 4 has a slope of 2 while the graphic -½x + 4 has a slope of -½

Step-by-step explanation:

[tex]{ \sf{y = mx + b}}[/tex]

m is the slope

b is the y-intercept

Answer:

8x^2-1+3^2

Step-by-step explanation:

Answer:

0

Step-by-step explanation:

r=5

So

=5⁴-5(5)³-4(5)²+5(5)+75

=5⁴-5(125)-4(25)+5(5)+75

=625-625-100+25+75

=0

Answer:

The orginal number is 26.

Step-by-step explanation:

So the units digit can be 3 6 or 9

The tens digit can be 1 2 or 3

So the original number can be 13

31 = 2*13+ (1+3) + 2

31 =? 26 + 4 + 2    

This doesn't work. The right side is 32

26

62 = 2*26 + 8 + 2

62 = 52 + 8 + 2

This is your answer.

3 and 9 won't work because 39 is odd and so is 93. The result has to be even.

Answer:

Thamkhao

Step-by-step explanation:

Answer:

76.50

Step-by-step explanation:

We are given the fact that you bought an object for 90 dollars, and in which you sold said object for a loss of 15%, we are then asked how much would that object be sold for.

To find the answer, we need to subtract the original amount by the percent loss, so :

90 - 15%

15% of 90 is 13.5, therefore :

90 - 13.5

76.5

Answer:

[tex] x = \frac {30}{r} + 2 [/tex]

Step-by-step explanation:

Given the following data;

To find how many times greater is the S.A compared to the area, we would have to divide the surface area (S.A) of the cylinder by the area of circle.

Let the unknown variable be x.

[tex] x = \frac {30 \pi r + 2 \pi r^{2}}{\pi r^{2}} [/tex]

Factorizing the numerator, we have;

[tex] x = \frac {\pi r(30 + 2r)}{\pi r^{2}} [/tex]

Dividing both sides by πr, we have;

[tex] x = \frac {30 + 2r}{r} [/tex]

Simplifying further, we would have;

[tex] x = \frac {30}{r} + 2 [/tex]

Answer:

The x-intercepts are reflecting zero-profit: (0, 0) and (6, 0).

The maximum value of the graph is at vertex (3, 120): maximum profit when the price is $3.

The function is increasing until the vertex, between x-value of 0 to 3 and is decreasing once it reached the vertex, between x-value of 3 to 6.

In the first interval the sale and profit increases, in the second interval the sale and profit decreases.

Average rate of change from x = 3 to x = 5 is:

This represents the profit drop of $30 per $1 price increase when price changes from $3 to $5.

after each year it's 83% of it's value from last year (100%-17%=83%)

the function in 19000 * (0.83) ^x

3 will be filled in for x

19000 * (0.83) ^3= 10863.953

$10863.95

Answer:

$10,863.95

Step-by-step explanation:

y = 19,000[tex](.83)^{t}[/tex]

y = 19,000[tex](.83)^{3}[/tex]

y =$10,863.95

Answer:

(0,8)

Step-by-step explanation:

To get the y-intercept put all x values equal to 0 (because we want to see where y lies on the graph when x is zero.

y=2^0+3

y=2^3

y=8

The y-intercept is (0,8)

As for the rest of the answers.....

1)A) 2[tex]\sqrt{12}[/tex]-5[tex]\sqrt{3}[/tex] = 4[tex]\sqrt{3}[/tex]-5[tex]\sqrt{3}[/tex] so the final answer is -[tex]\sqrt{3}[/tex]

1B) the problem is (3-[tex]\sqrt{7}[/tex])(3+[tex]\sqrt{7}[/tex]) a quick formula to help you solve this type of problem is (a-b)(a+b)= a^2-b^2 so you transform the question to 3^2-[tex]\sqrt{7}[/tex] ^2

to get 9-7 which is 3 therefore the final answer is 3

2) when you transform a function from y=x^2-3 to y=x^2+1 the graph moves 4 units up. So the final answer is b)4 units up

Question 3a and 3b are correct

Answer: 13

Step-by-step explanation:

Take 7 to the other side and divide 91 by 7, the answer will be 13.

I have to give 2 Ans form my question so sorry

Answer:

C. 2.

Step-by-step explanation:

The graph descends from the left  so the coefficient of the leading term is negative. It is also a cubic equation with zeros of -20, about 6.5 and about 13. so we can write the equation as below.  The last 2 values can only be guessed because the x axis only shows values which are multiples of 5.

f(x) = a(x + 20)(x - 6.5)(x - 13)   where a is  a negative constant.

(This is only an approximation).

By the Remainder theorem, when the expression is divided by (x + 10):

f(-10) = -20 so we have

-20 = a (-10 + 20)(-10-6.5)(-10 - 13)

(10)(-16.5)(-23)a = -20

a = -20 / (10)(-16.5)(-23)

a = -0.0053

When  the equation is divided by (x - 10) then f(10)  is the remainder so substituting we have as the remainder:

-0.0053(10+20)(10-6.5)(10 -13)

-0.0053 * 30 * 3.5 * -3

= 1.7 approximately.

Looks like the answer is 2.

BECAUSE ACCORDING TO THE PERIMETER (TRIANGLE ) FORMULA = B * H / 2.

B = BASE.

H = HEIGHT.

THE HEIGHT IS A VARIABLE VLAUE NEEDED IN ORDER TO ONTINUE TO SOLVE AND EVENTUALLY LEADING TO THE ANSWER (TRIANGLE PERIMETER.

Answer:

Area=9:25 Volume=81:625

Step-by-step explanation:

Should be squared, might be wrong.

Si yo tendria que sumar esos numeros daria: 21.61

porque, 6x1.10= 6.60

5x0.89= 4.45

y las tres cajas de cereal 3x3.52

Answer:

(1, 2)

Step-by-step explanation:

Given the equation of the lines x + 2y = 5 and 2x - 3y = -4

First we need to make x the subject of the formulas

For x+2y = 5

x = 5 - 2y ... 1

For 2x - 3y = -4

2x = -4+3y

x = (-4+3y)/2 ... 2

Equate 1 and 2

5 - 2y =  (-4+3y)/2

2(5-2y) = -4+3y

10 - 4y = -4+3y

-4 -3y = -4-10

-7y = -14

y = 14/7

y = 2

Substitute y = 2 into 1

x = 5 = 2y

x = 5 - 2(2)

x = 5 - 4

x = 1

Hence the point where the lines meet will be at (1, 2)

Answer:

[tex]-5x^2-5x[/tex]

Step-by-step explanation:

[tex]-5x\left(x+1\right)\\\\-5x\left(x+1\right)=-5xx-5x\cdot \:1\\\\=-5xx-5x\cdot \:1\\\\=-5x^2-5x[/tex]

Answer:

-5x^2 -5x

Step-by-step explanation:

-5x(x+1)

Distribute

-5x*x  +-5x*1

-5x^2 -5x