Question

The surface area of a cube is 864 in2. What is the area of one face of this cube?

Answer 1

A cube has six identical faces, so the surface area is six times the area of one face.

Let x be the area of one face.
$6x=864 \\ x=\frac{864}{4} \\ x=144$

The area of one face of this cube is 144 in².

Answer 2

$S=6a^{2} \\ \\ 6a^{2}=864 \\ \\ a^{2}=144$