helpppp asap!!!!!!

Question

What is the area of the rectangle that has dimensions of 21 − 3r inches by 5r − 17 inches and a perimeter of 32 inches? 

Answer 1

(21-3r) by (5r-17)

with perimeter = 32=

P/2 = 32/2 = 16 = L+W = 21-3r + 5r-17 = 4+2r

4+2r = 16

2r = 12

r =6

21-3r = 21-18=3

5r-17 = 30-17 = 13

It's 3 inches by 13 inches

Area = LW = 13(3) = 39 square inches

A= 39 in^2