-7b - 4(b + 7) = -3b - 4(b-2)

b = -9

Step-by-step explanation:

-7b - 4(b + 7) = -3b - 4(b -2)

First we want to distribute the coefficients across the parentheses. To do so, we multiply the coefficient by every term within the parentheses.

-7b - 4(b + 7) = -3b - 4(b - 2)

-4 • b = -4b

-4 • 7 = -28

-4 • b = -4b

-4  • -2 = 8

Simplify the expression with these new values.

-7b - 4b - 28 = -3b - 4b + 8

Now we want to combine the like terms. First combine the variables.

-7b - 4b - 28 = -3b - 4b + 8

-11b - 28 = -7b + 8

Combine further by adding 7b to both sides.

-4b - 28 = 8

Combine the constants by adding 28 to both sides.

-4b = 36

Isolate b by dividing both sides by -4.

b = -9

This is your answer.

Check your answer by plugging b = -9 back into the original equation.

-7b - 4(b + 7) = -3b - 4(b - 2)

-7(-9) - 4(-9 + 7) = -3(-9) - 4((-9) - 2)

63 - 4(-2) = 27 - 4(-11)

63 + 8 = 27 + 44

71 = 71

Your answer is correct.

Hope this helps!

-9 is the required answer of b

Step-by-step explanation:

-7b - 4(b + 7) = -3b - 4(b-2)

open bracket

-7b-4b-28=-3b-4b+8

-11b-28=-7b+8

-11b+7b=28+8

-4b=36

b=36/-4=-9

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

you can not solvr this without numbers