Answer
$SA = 10x^2+38x+30$
Work Step by Step
$SA = 2*w*l + 2*w*h + 2*h*l$
$SA = 2*(x)(2x+5) + 2*(2x+5)(x+3)+2*(x)(x+3)$ (replacing variables with dimensions)
$SA = 2*(2x^2+5x)+2*(2x^2+6x+5x+15)+2*(x^2+3x)$ (distributing the variables)
$SA = 4x^2+10x+4x^2+12x+10x+30+2x^2+6x$ (simplifying the variables)
$SA = 10x^2+38x+30$ (combining like terms)
