so, let's say the length is "L".
width = 2 shorter than L = L - 2.
height = 9 more than twice L = 2L + 9.
check the picture below.
keeping in mind that the volume of a <u>rectangular prism</u> is simply the product of its length, width and height, and since we know the volume has to be 45.

![\bf \stackrel{\textit{again common factor}}{0=\underline{(2L+5)}(L^2-9)}\implies \stackrel{\textit{difference of squares}}{0=(2L+5)\stackrel{\downarrow }{(L^2-3^2)}} \\\\\\ 0=(2L+5)(L-3)(L+3)\implies L= \begin{cases} -\cfrac{5}{2}\\[1em] \boxed{3}\\ -3 \end{cases}](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7Bagain%20common%20factor%7D%7D%7B0%3D%5Cunderline%7B%282L%2B5%29%7D%28L%5E2-9%29%7D%5Cimplies%20%5Cstackrel%7B%5Ctextit%7Bdifference%20of%20squares%7D%7D%7B0%3D%282L%2B5%29%5Cstackrel%7B%5Cdownarrow%20%7D%7B%28L%5E2-3%5E2%29%7D%7D%20%5C%5C%5C%5C%5C%5C%200%3D%282L%2B5%29%28L-3%29%28L%2B3%29%5Cimplies%20L%3D%20%5Cbegin%7Bcases%7D%20-%5Ccfrac%7B5%7D%7B2%7D%5C%5C%5B1em%5D%20%5Cboxed%7B3%7D%5C%5C%20-3%20%5Cend%7Bcases%7D)
from those 3 factors, we get those solutions/zeros.
we can't use -5/2, or -3, because the length can't be a negative value, so L = 3.
that means the width = 3 + 2, and the height = 2(3) +9.