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put this solution on YOUR website!A rectangular box is (3x + 7) feet wide, (6x + 3) feet long, and (7x - 1) feet high. Find the volume of this box.
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It's the same as any other rectangular solid, l*w*h
V = (3x+7)*(6x+3)*(7x-1)
= (18x^2 + 51x + 21)*(7x-1)
= 126x^3 - 18x^2 + 357x^2 - 51x + 147x - 21
=126x^3 + 339x^2 + 96x - 21 cubic feet
