he perimeter of a rectangle is 18 inches and its area is 20 square inches. What are its​ dimensions?

Question

he perimeter of a rectangle is 18 inches and its area is 20square inches. What are its dimensions?

Answer 1

P=2l+2w

A=lw

18=2l+2w

9=l+w

l=9-w

A=(9-w)w

20=9w-w^2

w^2-9w+20=0

factor

(w-5)(w-4)=0

w-5=0

w=5 inches

w-4=0

w=4 inches

the rectangle is a 4 x 5 rectangle

the simplest thing to do is factor 20

20=2*2*5=4*5 and 4+5=9 and 2*9=18