Answer
i) Zeros: $x=6$ and $x=-4$
ii) Axis of symmetry: $x= 1$
iii) Vertex: $(1,-7.5)$
Work Step by Step
The function can be written in factored form as follows.
$$
\begin{aligned}
y & =0.3 x^2-0.6 x-7.2 \\
& =0.3\left(x^2-2 x-24\right) \\
& =0.3(x-6)(x+4)
\end{aligned}
$$
Therefore, the zeros are at $x=6$ and $x=-4$.The axis of symmetry is midway between the zeros, so its equation is $x =\frac{6-4}{2}= 1$.
substituting $x=1$ into $y$ gives $y=0.3(1-6)(1+4)=-7.5$.
