Find the length and width

The perimeter of a rectangle if 68 feet. If the length is 8 feet more than the width, find both the length and width.  (Formula: P = 2L + 2W)

x = width
x + 8 = length   {the length is 8 more than the width} 
 
Perimeter of a rectangle is 2(width) + 2(length)

2x + 2(x + 8) = 68   {substituted expressions into perimeter formula}
2x + 2x + 16 = 68   {used distributive property}
4x + 16 = 68   {combined like terms}
4x = 52   {subtracted 16 from each side}
x = 13 ft width   {divided each side by 4}
 x + 8 = 21 ft length   {substituted 13, in for x, into x + 8}

width is 13 ft
length is 21 ft

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