The length, width, and height of a rectangular prism can be represented by the expressions (x+3), (x+7) and (x-1). write an expression to represent the surface area of the prism.

The surface area = 2LW + 2LH + 2WH     where W = width, L = length and H = height 

So here we have 
Surface Area =  2(x+3)(x+7) + 2(x+3)(x-1) + 2((x+7)(x-1)

 = 2x^2 + 20x + 42 + 2x^2 + 4x - 6 + 2x^2 + 12x - 14

=  6x^2 + 36x + 22