The formula for the permit of the rectangle is, p = 21 + 2w

Question

Where p is the perimeter, I is the length of the rectangle, and w is the width of the rectangle.

Rearrange the equation to solve for I (length), then use your equation to find the length of a rectangle with a perimeter of 12cm and a width of 2.5cm.

(Show your equation and your solution.)

Answer 1

The formula for the perimiter of a rectangle is p = 2l + 2w. The question is asking us to solve for l in this formula. In order to do that, we do the following:

p = 2l + 2w Subtract 2w to the other side to isolate l

p - 2w = 2l Divide by 2 to solve for l

l = (p - 2w)/2

Now we have to use this equation to solve for l if p = 12 cm and w = 2.5 cm

l = (p - 2w)/2 Let's plug in our values first

l = (12 - (2 * 2.5))/2 Let's multiply 2 by 2.5 to get 5

l = (12 - 5)/2 Now subtract 12 by 5 to get 7

l = 7/2 Now divide 7 by 2 to get 3.5

l = 3.5 cm