Answer:
A=2wl+2lh+2hw
A=2(x+7)(x+3)+2(x+3)(x-1)+2(x-1)(x+7)
A=2(x^2+7x+3x+21)+2(x^2-x+3x-3)+2(x^2+7x-x-7)
A=2(x^2+10x+21)+2(x^2-2x-3)+2(x^2+6x-7)
Answer:
6x²+36x+22
Step-by-step explanation:
Surface Area = 2(wl + hl + wh)
Length = (x+3)
Width = (x+7)
Height = (x-1)
Surface Area = 2((x+7)(x+3) + (x-1)(x+3) + (x+7)(x-1))
Then simplify
2((x+7)(x+3)+(x−1)(x+3)+(x+7)(x−1))
=(2)((x+7)(x+3)+(x−1)(x+3)+(x+7)(x−1))
=(2)((x+7)(x+3))+(2)((x−1)(x+3))+(2)((x+7)(x−1))
=2x²+20x+42+2x²+4x−6+2x²+12x−14
=6x²+36x+22
