Answer
The value of $\left( g\circ f \right)\left( -1 \right)$ is $-5$.
Work Step by Step
The composition of f with g can be defined as the function $\left( f\circ g \right)$ and $\left( f\circ g \right)\left( x \right)$ which is equivalent to $f\left( g\left( x \right) \right)$.
Consider the equation below
$\left( g\circ f \right)\left( -1 \right)=g\left( f\left( -1 \right) \right)$
Here,
$f\left( -1 \right)=1$.
Then,
$g\left( f\left( -1 \right) \right)=g\left( 1 \right)$
And value of $g\left( 1 \right)=-5$.
Hence, $\left( g\circ f \right)\left( -1 \right)=-5$
Hence, the value of $\left( g\circ f \right)\left( -1 \right)$ is $-5$.
