Answer:
5x-1.
Explanation:
We have been the formula for the volume of a rectangular prism as:
and the lengths are (x+2) and (x+4).
Since we know that volume of a rectangular prism is length times width times height, so to find the our missing length we will divide volume of rectangular prism by the given side length.
![\text{Missing side}=(5x^3+29x^2+34x-8)/((x+2)(x+4))](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5siopao6nlvn0j1ej8ho86m1tlqnjochgq.png)
![\text{Missing side}=(5x^3+29x^2+34x-8)/(x^2+6x+8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/moypyi6twvd1vvc9ehj5uotpzz0o9a3nk0.png)
![\text{Missing side}=((5x-1)(x^2+6x+8))/(x^2+6x+8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/huhql0gs81vq126z9crcwzbjriu1gb3vja.png)
![\text{Missing side}=(5x-1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/194tpjbme2mfnuiamij2oe0wogu3kwuxr5.png)
Therefore, missing length of the rectangular prism is 5x-1.