Question

what is the y value of this minimum??

Answer 1

Since they give us that x=3, and give us the formula, we can plug 3 in for x in the formula in order to solve for y

y= -x²+6x-7

y = -(3)²+6(3)-7

y = -9+18-7

y = 2

Answer 2

The answer is y = 2.

In this problem, you just need to plug the x value to the equation:
$y = - {x}^{2} + 6x - 7 \\ \\ y = - {3}^{2} + 6 \times 3 - 7 \\ \\ y = - 9 + 18 - 7 \\ \\ y = 2$