a so-called zero or solution is really just an x-intercept, in which case we set the dependent variable to 0, namely y = h(x) = 0 and solve for x to get it.
[tex] \bf h(x)=4x^2-8x-60\implies \stackrel{h(x)}{0}=4x^2-8x-60\implies \stackrel{\textit{dividing by 4}}{0=x^2-2x-15}
\\\\\\
0=(x-5)(x+3)\implies x=
\begin{cases}
5\\
\boxed{-3}
\end{cases} [/tex]
why is -3 the smallest? well, -3 is much smaller than 5 :), the further to the left you go on the number line, the smaller the number.
