Thread: Another quad formula word prob

Block 4 by 5 by 3 feet. Wants to reduce volume by shaving off the same amount from length width and height.

Could you give me a clue as to where I should start? I know I have to make a quad formula.

The answer is -x^3+12x^2-47x+60

If we're subtracting the same amount from each value:



Substitute in for the values of h, w, and l:



Multiply it out:






Also, it isn't quadratic, but rather, a cubic...but I suppose you make a quadratic in one of the intermediate steps.