#### Answer

The function $h\left( x \right)$ can be written as a composition of the functions $f\left( x \right)={{x}^{4}}\text{ and }g\left( x \right)={{x}^{2}}+2x-1$.

#### Work Step by Step

Consider the functions $f\left( x \right)={{x}^{4}}$ and $g\left( x \right)={{x}^{2}}+2x-1$.
Then,
$\begin{align}
& h\left( x \right)={{\left( {{x}^{2}}+2x-1 \right)}^{4}} \\
& =f\left( g\left( x \right) \right)
\end{align}$
Hence, the function x can be written as a composition of the above functions.