The equation and graph of a polynomial are shown below. The graph reaches its maximum when the value of x is 3. What is the y-value of this maximum? y=-x+6x-8

The maximum value of y is
[tex]Y=x^2+6x-8[/tex][tex]y=(3)^2+6(3)-8[/tex][tex]\begin{gathered} y=\text{ 9+18-8} \\ y=19 \end{gathered}[/tex]So, the maximum value of y when x=3 is 19