SA : 2( wl + lh + hw)
Our width is x centimeters, length is x +4 centimeters and the height is 15 centimeters. Then, we will plug it in.
SA : 2 ( x ( x + 4) + ( x + 4 ) 15 + 15 ( x) )
Then, let's distribute the terms.
2 ( ( x^2 + 4x) + (15x + 60) + 15x
2x^2 + 8x + 30x + 120 + 30x
2x^2 + 68x + 120 = 264
2x^2 + 68x - 144
Factor it out:
(x-2)(x+36)
x -2 = 0
+ 2
x = 2
Plug it in.
V = 2(2 + 4)(15)
V = 2(6 x 15)
V = 2 x 90
V = 180
V = 180cm^3