## Basic College Mathematics (10th Edition)

Length $= 168$ ft Width $= 42$ ft
$x =$ width $4x =$ length 1. Find $x$ Let $P =$ perimeter of the rectangle $2(4x) + 2(x) = 420$ $8x + 2x = 420$ $10x = 420$ $x = 42$ 2. Substitute $x$ into the length and width equations a) Width $x = 42$ ft Therefore the width of the rectangular building is $= 42$ ft b) Length $4x = 4(42)$ $4x = 168$ ft Therefore the length of the rectangular building is $= 168$ ft.