Answer
According to the graph the x-intercepts are: $(3,0)$ and $(-15,0)$
Work Step by Step
$f(x)=0$
$\frac{7}{10}(x^2+12x-45)=0~~$ (Divide both sides by $\frac{7}{10}$)
$x^2+12x-45=0~~$ ($a=1,b=12,c=-45$):
$x=\frac{-12±\sqrt {12^2-4(1)(-45)}}{2(1)}=\frac{-12±\sqrt {324}}{2}=\frac{-12±18}{2}=-6±9$
$x=3$ or $x=-15$
x-intercepts: $(3,0)$ and $(-15,0)$
