X + 12 = 20 i really need help

The expression 6x2 gives the surface area of a cube, and the expression x3 gives the volume of a cube, where x is the length of one side of the cube. find the surface area and the volume of a cube with a side length of 6m

What value of x is in the solution set of 4x - 12 s 16 + 8x? -10 -9 -8 -7

You eat $0.85 for every cup of hot chocolate you sell. how many cups do you need to sell to earn $55.25