What is the value of x? - 2 ( 3x - 5 ) = 16

x = -1

Step-by-step explanation:

Given: - 2 ( 3x - 5 ) = 16

To solve for x, we must isolate the variable x.

First, we distribute the negative two inside the parentheses.

-6x + 10 = 16

Now, we'll move the ten to the other side by subtracting it.

-6x + 10 = 16

      -10      -10

16 - 10 = 6, so

-6x = 6

Lastly, we'll divide the number by itself to get the variable alone.

Six divided by negative six is negative one, therefore,

x = -1

(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