The perimeter of a rectangular movie screen at a local cinema is 148 feet. If the length of the screen is 30 feet longer than the width, what is the length of the screen, in feet?

The perimeter of a rectangle = 2(l + w)

l = length

w = width

In this problem,

w = x

l = x + 30

the perimeter = 148

Let's plug our values into the perimeter formula above.

148ft = 2(x + x + 30ft)

Combine like terms.

148ft = 2(2x + 30ft)

Distribute the 2

148ft = 4x + 60

Subtract 60 from both sides

88ft = 4x

Divide both sides by 4

22ft = x

The width = x = 22ft

The length = x + 30 = 22 + 30 = 52ft