Ask question

Ask question

All categories

2 years ago

7

Factorize completely 81k^2 - m^2

2 answers:

Genrish500 [490]2 years ago

7 0

81k^2 - m^2 factors to

(9k + m)(9k - m)

Prove this by FOILing.

First - 81k^2

Outer - (-9km)

Inner - 9km

Last - (-m^2)

Put it into equation form

81k^2 - 9km + 9km - m^2

And combine terms to get the original equation,

81k^2 - m^2.

⭐ Answered by Hyperrspace (Ace) ⭐

⭐ Brainliest would be appreciated, I'm trying to reach genius! ⭐

⭐ If you have questions, leave a comment, I'm happy to help! ⭐

PolarNik [594]2 years ago

5 0

(9k+m) X (9k - m)

Step-by-step explanation:

81 $k^{2}$ - $m^{2}$

= (9k)^2 - (m)^2 ( taking the square roots)

=(9k+m) (9k - m)

here we have applied the rules of a^2 - b^2 = ( a+b) ( a -b)

here 9k is taking as a and m is taking as b

thus you get your answer.

hope it helps.

You might be interested in

How do i simplify this

Ray Of Light [21]

<h3>I'll teach you how to solve sqrt 150</h3>

---------------------------------------------------------

sqrt 150

Prime factorization:

sqrt 2*3*5^2

Apply radical rule:

sqrt 2*3 sqrt 5^2

Apply radical rule:

sqrt 2*3 *5

Multiply the numbers:

$5\sqrt{6}$

Your Answer Is (C) $5\sqrt{6}$

plz mark me as brainliest :)

7 0

2 years ago

Read 2 more answers

An equiangular triangle can be a scalene?

Lorico [155]

Answer:

No, an equiangular triangle cannot be scalene.

Step-by-step explanation:

By definition, a scalene triangle is a triangle in which each side of the triangle has a different length

6 0

2 years ago

Canadians who visit the United States often buy liquor and cigarettes, which are much cheaper in the United States. However, the

fenix001 [56]

Answer:

(a): Marginal pmf of x

$P(0) = 0.72$

$P(1) = 0.28$

(b): Marginal pmf of y

$P(0) = 0.81$

$P(1) = 0.19$

(c): Mean and Variance of x

$E(x) = 0.28$

$Var(x) = 0.2016$

(d): Mean and Variance of y

$E(y) = 0.19$

$Var(y) = 0.1539$

(e): The covariance and the coefficient of correlation

$Cov(x,y) = 0.0468$

$r \approx 0.2657$

Step-by-step explanation:

Given

<em>x = bottles</em>

<em>y = carton</em>

<em>See attachment for complete question</em>

<em />

Solving (a): Marginal pmf of x

This is calculated as:

$P(x) = \sum\limits^{}_y\ P(x,y)$

So:

$P(0) = P(0,0) + P(0,1)$

$P(0) = 0.63 + 0.09$

$P(0) = 0.72$

$P(1) = P(1,0) + P(1,1)$

$P(1) = 0.18 + 0.10$

$P(1) = 0.28$

Solving (b): Marginal pmf of y

This is calculated as:

$P(y) = \sum\limits^{}_x\ P(x,y)$

So:

$P(0) = P(0,0) + P(1,0)$

$P(0) = 0.63 + 0.18$

$P(0) = 0.81$

$P(1) = P(0,1) + P(1,1)$

$P(1) = 0.09 + 0.10$

$P(1) = 0.19$

Solving (c): Mean and Variance of x

Mean is calculated as:

$E(x) = \sum( x * P(x))$

So, we have:

$E(x) = 0 * P(0) + 1 * P(1)$

$E(x) = 0 * 0.72 + 1 * 0.28$

$E(x) = 0 + 0.28$

$E(x) = 0.28$

Variance is calculated as:

$Var(x) = E(x^2) - (E(x))^2$

Calculate $E(x^2)$

$E(x^2) = \sum( x^2 * P(x))$

$E(x^2) = 0^2 * 0.72 + 1^2 * 0.28$

$E(x^2) = 0 + 0.28$

$E(x^2) = 0.28$

So:

$Var(x) = E(x^2) - (E(x))^2$

$Var(x) = 0.28 - 0.28^2$

$Var(x) = 0.28 - 0.0784$

$Var(x) = 0.2016$

Solving (d): Mean and Variance of y

Mean is calculated as:

$E(y) = \sum(y * P(y))$

So, we have:

$E(y) = 0 * P(0) + 1 * P(1)$

$E(y) = 0 * 0.81 + 1 * 0.19$

$E(y) = 0+0.19$

$E(y) = 0.19$

Variance is calculated as:

$Var(y) = E(y^2) - (E(y))^2$

Calculate $E(y^2)$

$E(y^2) = \sum(y^2 * P(y))$

$E(y^2) = 0^2 * 0.81 + 1^2 * 0.19$

$E(y^2) = 0 + 0.19$

$E(y^2) = 0.19$

So:

$Var(y) = E(y^2) - (E(y))^2$

$Var(y) = 0.19 - 0.19^2$

$Var(y) = 0.19 - 0.0361$

$Var(y) = 0.1539$

Solving (e): The covariance and the coefficient of correlation

Covariance is calculated as:

$COV(x,y) = E(xy) - E(x) * E(y)$

Calculate E(xy)

$E(xy) = \sum (xy * P(xy))$

This gives:

$E(xy) = x_0y_0 * P(0,0) + x_1y_0 * P(1,0) +x_0y_1 * P(0,1) + x_1y_1 * P(1,1)$

$E(xy) = 0*0 * 0.63 + 1*0 * 0.18 +0*1 * 0.09 + 1*1 * 0.1$

$E(xy) = 0+0+0 + 0.1$

$E(xy) = 0.1$

So:

$COV(x,y) = E(xy) - E(x) * E(y)$

$Cov(x,y) = 0.1 - 0.28 * 0.19$

$Cov(x,y) = 0.1 - 0.0532$

$Cov(x,y) = 0.0468$

The coefficient of correlation is then calculated as:

$r = \frac{Cov(x,y)}{\sqrt{Var(x) * Var(y)}}$

$r = \frac{0.0468}{\sqrt{0.2016 * 0.1539}}$

$r = \frac{0.0468}{\sqrt{0.03102624}}$

$r = \frac{0.0468}{0.17614266944}$

$r = 0.26569371378$

$r \approx 0.2657$ --- approximated

8 0

2 years ago

MATH is getting crazy can someone help me

WARRIOR [948]

Answer:

70 and (100%)(40)+(80)(40)

Step-by-step explanation:

hh

6 0

2 years ago

Read 2 more answers

Is it more difficult to run up a ramp with a slope of 1/5 or a ramp with a slope of 5? Explain.

VARVARA [1.3K]

It would be more difficult to run up a slope of 5 because it would be steeper. with a 1/5 slope you would have a rise over run but with a slope of 5 it would just be all rise

6 0

2 years ago

Read 2 more answers