## Precalculus (6th Edition) Blitzer

${{g}^{-1}}\left( 7 \right)=2$
This value of the given function can be obtained using the definition of functions and the value of $g$ at the required point. Assume, ${{g}^{-1}}\left( 7 \right)=x$ , then $g\left( x \right)=7$. Since the value of $g\left( x \right)=4x-1$ , thus we have \begin{align} & 4x-1=7 \\ & 4x=8 \\ & x=2 \end{align} Thus, ${{g}^{-1}}\left( 7 \right)=x=2$.