The volume for a pyramid is
![V= (1)/(3) Bh](https://img.qammunity.org/2019/formulas/mathematics/college/eaka46yu4j72p7qu4xis19ba4d9pbbwxpl.png)
, where B is the area of the base and h is the height. We are given the volume, and the base and height in terms of x. Our formula then looks like this:
![768= (1)/(3) (x)( (1)/(6) x)](https://img.qammunity.org/2019/formulas/mathematics/college/hl7prjfjrw3sb193ibrdn0s2ajasnv3kcb.png)
. Simplifying the right side we have
![768= (1)/(18) x^(2)](https://img.qammunity.org/2019/formulas/mathematics/college/fytktnvvs9bo59vrft233ffoxhsai2n2ej.png)
. Multiply both sides by 18 to get rid of the fraction and we have
![13824= x^(2)](https://img.qammunity.org/2019/formulas/mathematics/college/e7uj8ff35hraaqent09y0cf8g2ifvwubft.png)
, so x = 117.575