Question

I need help on a practice sheet

Answer 1

`\begin{gathered} x^3+2y^2-z \\ \\ \text{If } \\ x=3 \\ y=-5 \\ z=-1 \\ \\ Substitute\text{ the given values and evaluate:} \\ (3)^3+2(-5)^2-(-1) \\ =(3\cdot3\cdot3)+2(-5\cdot-5)+1 \\ =27+2(25)+1 \\ =27+50+1 \\ =78 \end{gathered}`