polynomial equations and functions

Question

An open box is to be made from a cardboard. The width of the cardborad is 5inches lee than the length by cutting 4 inch squares from each corner and folding up the sides. If the volume of the box is 336cubic inches, find the dimensions. of the original cardboard.

Answer 1

original cardboard was 29x24 inches

W=L-5

(L-8)(W-8) = 336

(L-8)(L-5-8) = 336

(L-8)(L-13) = 336

L^2 - 21L -232 = 0

(L-29)(L+24) =0

L=29 inches long

W =29-5 = 24 inches wide

(29-8)(24-8) = (21)(16) = 336 sq. in.

Answer 2

Draw and label a diagram!

w represents the original width

w + 5 represents the original length

(w - 2(4))(w + 5 - 2(4))(4) = 336

Can you solve for w and answer?