Algebra word problem. Please help?
The length of a rectangle is 15 cm more than its width w. A blue rectangle, which is 5 cm wider and 2 cm shorter than the red one, has perimeter 72 cm. Find the dimension of each rectangle. I've been trying to figure this out for the past half our, and I don't understand it. Please help! Thank you
Comments
Perimeters are 2L + 2W
Red rectangle is L= W+15; W = W
Blue Rectangle: L = W+15-2; W = W+5; P = 72cm
2(W+15-2)+2(W+5) = 72
2(W+13)+2(W+5) = 72
2W+26+2W+10 = 72
4W+36 = 72........4W = 72-36
4W = 36; then, W = 36/4 or 9 cm.
Red Rectangle: L = W+15; L = 9+15; L = 24 CM
Red Rectangle: W = 9 cm
Red Rectangle Perimeter is 2(9)+2(24) = 18+48 = 66 cm.
Blue Rectangle: L = W+15-2 = 9+15-2 = 22 cm
Blue Rectangle: W = W+5 = 9+5 = 14
Blue Rectangle Perimeter is 2(22)+2(14) = 44+28 = 72 cm.