Question

Vertex of the graph of y=x^2+4x

Answer 1

x = -b/2a
x = -4/2 = -2
To find y, plug -2 back into original function.
y = (-2)^2 + 4(-2)
y = 4 - 8
y = -4
Vertex (-2,-4)

Answer 2

The answer is (-2,-4)