Answer
$x=\frac{2}{3}$
$x=-8$
Work Step by Step
$f(x)=0$
$3x^2+22x-16=0$ ($a=3,b=22,c=-16$):
$x=\frac{-b±\sqrt {b^2-4ac}}{2a}=\frac{-22±\sqrt {22^2-4(3)(-16)}}{2(3)}=\frac{-22±\sqrt {676}}{6}=\frac{-22±26}{6}$
$x=\frac{4}{6}=\frac{2}{3}$
or
$x=\frac{-48}{6}=-8$
