Question

One side of a rectangle is 20 cm larger than the other side. If you make the smaller side two times larger and the larger side three times larger, then the perimeter of the new rectangle would be 240 cm. Find the lengths of the sides of the original rectangle.

Answer 1

Let L be the length
Let w be the width
Let p be the perimeter
L+w+L+w=p
L=w+20
3L+2w+3L+2w=240
Sub the first equation in for L in the second equation and solve for w
3(w+20)+2w+3(w+20)+2w=240
3w+60+2w+3w+60+2w=240
10w+120=240
10w=240-120
10w=120
W=120/10
W=12
Sub w into the first equation and solve for L
L=w+20
L=12+20
L=32
Hope this helps!