Answer:
Step-by-step explanation:
a sandbox is the same at a rectangular prism
the formula is base times height.
to find base multiply width (10-x) times length (14-x)
this would be
simplified is
x^2-24x+140. This is the perimeter of the base (bottom) of the sandbox
answer is 362,880
9!= 9×8×7×6×5×4×3×2×1=362,880