Answer
(a) $f(-5)=-3$
(b) $f(-1)=1$
(c) $f(0)=0$
(d) $f(3)=9$
Work Step by Step
To evaluate the piecewise-defined function, identify the 'piece' of the function that covers the given value of $x$. Then substitute, the given value of $x$.
(a) $f(-5)$
For $x=-5$ the function is defined by $2+x$.
Thus, $f(-5) = 2+(-5)=-3$
(b) $f(-1)$
For $x=-1$ the function is defined by $-x$.
Thus, $f(-1) = -(-1)=1$
(c) $f(0)$
For $x=0$ the function is defined by $-x$.
Thus, $f(0) = -0=0$
(d) $f(3)$
For $x=3$ the function is defined by $3x$.
Thus, $f(3) = 3(3)=9$
