First, make an equation system based on the problem An equation for "<span>she has enough bricks to cover 108 square feet" is </span>∴ l × w = 108 An equation for "<span>she wants the length of the patio to be 12 feet greater than the width" is </span>∴ l = w + 12 <span> Second, solve the equation system by subtitution l </span>× w = 108 (w + 12)w = 108 w² + 12w = 108 w² + 12w - 108 = 0 (w + 18)(w - 6) = 0 w = -18 or w = 6 Because a width shouldn't be negative, -18 isn't required. The width of the patio is 6 feet.
Subtitute w with 6 l = w + 12 l = 6 + 12 l = 18 The length of the patio is 18 feet.
