Express your length and width as algebraic expressions:
width = x
length = 4x
Use the formula for the perimeter of a rectangle to solve for x:
perimeter = 2(length) + 2(width)
50 = 2(4x) + 2(x)
50 = 8x + 2x
50 = 10x
5 = x
The width (x) is 5 feet and the length (4x) is 20 feet.
