[tex]\bf (x)(x+2)=255\implies x^2+2x=255\implies x^2+2x-255=y
\\\\
\textit{setting y=0}\implies x^2+2x-255=0
\\\\
\textit{now, factoring that}
\\\\
(x+17)(x-15)=0\implies
\begin{cases}
x=-17\\
x=15
\end{cases}[/tex]
notice the picture of the graph added here
low and behold, x = -17, y is 0, and x= 15, y is 0
the graph is touching the x-axis, an x-intercept
or so-called, a "solution"
