Answer:
112 sq ft.
Explanation:
let the width of the first garden be x.
the length will be x+9
The area of this garden = x(x+9)
The width of the second garden is 6 more than the first
so width will be x+6
The length of the second garden = 2(x+9)
so the area of this garden = (x+6)*2(x+9)
The sum of their areas = 528ft^2
x(x+9)+2(x+6)(x+9)= 528
x^2+9x +2(x^2+15x+54)=528
x^2 +9x +2x^2+30x+108=528
3x^2+39x-420= 0
3(x^2+13x-140)=0
x^2+13x-140=0
x^2+20x-7x-140=0
x(x+20)-7(x+20)=0
(x+20(x-7)=0
x=7 the width of the first garden.
the length will be x+9 = 7+9
=16
Area of the garden = 16*7
= 112 sq. ft