Question 8afcf601

The functions $f$ and $g$ are defined as $f\left(x\right)=\frac{1}{4}x-9$ and $g\left(x\right)=\frac{3}{4}x+21$. If the function $h$ is defined as $h\left(x\right)=f\left(x\right)+g\left(x\right)$, what is the x-coordinate of the x-intercept of the graph of $y=h\left(x\right)$ in the xy-plane?