Answer
$x=\left\{ \dfrac{4}{3},7 \right\}$
Work Step by Step
Substituting $y$ with $317$ in $
y=3x^2-25x+345
,$ then
\begin{array}{l}\require{cancel}
317=3x^2-25x+345
.\end{array}
Using the properties of equality, the equation above is equivalent to
\begin{array}{l}\require{cancel}
3x^2-25x+345-317=0
\\
3x^2-25x+28=0
\\
(3x-4)(x-7)=0
.\end{array}
Equating each factor to zero (Zero Product Property) then the solutions of the equation above are $
x=\left\{ \dfrac{4}{3},7 \right\}
.$
