Question

A box is x inches high, (2x + 3) inches wide, and (2x + 5) inches long. In terms of x, what is the volume (V) of the box?

A) V = 4x3 + 15x


B) V = 4x3 + 4x2 + 5x


C) V = 4x3 + 4x2 + 15x


D) V = 4x3 + 16x2 + 15x

Answer 1

V = lwh
V = x(2x + 3)(2x + 5)
V = x(2x(2x + 5) + 3(2x + 5))
V = x(2x(2x) + 2x(5) + 3(2x) + 3(5))
V = x(4x² + 10x + 6x + 15)
V = x(4x² + 16x + 15)
V = x(4x²) + x(16x) + x(15)
V = 4x³ + 16x² + 15c

The answer is D.