Algebra-1

To find the vertex of the quadratic function y = x² + 18x + 80, we can use the vertex formula. In this case, the quadratic function is in the form y = ax² + bx + c, with a = 1, b = 18, and c = 80.

The x-coordinate of the vertex is given by x = -b / (2a). Plugging in the values, we get:

x = -18 / (2 * 1)
  = -18 / 2
  = -9

So, the x-...