In order to evaluate the function, we need to substitute the value -1 into the place of x, that is,
[tex]f(-1)=-4^{2(-1)+3}[/tex]which gives
[tex]\begin{gathered} f(-1)=-4^{-2+3} \\ f(-1)=-4^1 \end{gathered}[/tex]Therefore, the answer is:
[tex]f(-1)=-4[/tex]