Math Question #2

Question

The length of a rectangle is 7 inch more than its width. The area of the rectangle is 144 square inches. Find the dimensions of the rectangle.

Answer 1

Area=l*w

144=l*w

l=w+7

substitute the 2nd equation into the 1st

144=w(w+7) Multiply

144=w²+7w subtraction 144 from both sides

144-144=w²+7w-144

0=w²+7w-144 factor

(w+16)(w-9)=144

w+16= 0 subtract 16 from both side

w+16-16=0-16

w=-16 The width can’t be negative so this is an extraneous solution.

w-9=0 add 9 to both sides

w-9+9=0+9

width = 9 inches. Substitute into length equation length=w+7

length=9+7 length=16 inches.

The answer is the width equals 9 inches and the length equals 16 inches.