A toolbox is 2ft. high and its width is 3ft. less than its lenght. if its volume is 80ft.
We find volume by using V = H*W*L , where H = height , W = width, and L = length. You say H = 2 ft,
V = 80 ft ^3, and W = L - 3 . Put all of these back onto the equation and we will have
80 = 2 * (L - 3) * L . We can condense this to be 80 = (2*L - 2*3 ) * L then becomes 80 = 2*L*L - 2*3*L
simplifying this we get 40 = L*L - 3*L . This is also 40 = L * (L - 3) this is a quadratic equation, meaning that
we will get two answers for L. In this case L = 0 and L = 3. Since 0 ft would mean that the tool box doesn't
have a length we will use L = 3. We can now put this back into our original equation to find out what the
width is. 80 = 2 * W * 3, this is 80/6 = W = 13.3333 . Now we know that W = 13.3333 and L = 3.
Mar 07, 2011 |