Answer:
Area=400 square feets
Explanation:
width of rectangle=s-12
length of rectangle=s-5
Area of rectangle =120 square feet
area= L×W
={(s-12) (s-5)} = 120
=s(s-5) -12(s-5) = 120
= s^2 -5s -12s + 60 =120
= s^2 - 17s = 60
=s^2 - 17s - 60 = 0
product = -60;sum= -17} 3 ,-20
s^2+3s-20s-60 = 0
s(s+3)-20(s+3) =0
(s-20) (s+3) = 0
s=20 , s=-3
one side of the square =20ft
area = s×s
= 20×20
= 400 square feets