Question 60369
The maximum value will be on the line of symmetry for the equation is found using the formula {{{LOS = -b/2a}}} where a is the x squared coefficient and b is the x coefficient.
{{{LOS = -6/2(-1) = 3}}}

This means that the maximum y value occurs when the x value is 3. Substitute x =3 in the original equation.
{{{y = -3^2 + 6*3=-9+18=9}}}