The perimeter of the rectangle is 180 cm, and the width is 30 cm less than the length. find its length.

P = 180 cm
b 30 cm shorter than the length
l-?

decision

the perimeter of the rectangle is equal to the sum of all its sides, and the length and width are the same as the perimeter of the rectangle
equal to 2 lengths plus two widths.

We make the equation

let x be the length of the rectangle and x-30 the width.

It turns out the equation 2x + 2 (x-30) = 180

2x + 2x-60 = 180
4x = 240

x = 60 the length of the rectangle

Answer 60 cm