Answer
(a) $f(-5)=10$
(b) $f(-1)=-4$
(c) $f(0)=-1$
(d) $f(3)=-12$
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 $-2x$.
Thus, $f(-5) = -2(-5)=10$
(b) $f(-1)$
For $x=-1$ the function is defined by $3x-1$.
Thus, $f(-1) = 3(-1)-1=-3-1=-4$
(c) $f(0)$
For $x=0$ the function is defined by $3x-1$.
Thus, $f(0) = 3(0)-1=0-1=-1$
(d) $f(3)$
For $x=3$ the function is defined by $-4x$.
Thus, $f(3) = -4(3)=-12$
