Question

What is the x-coordinate of the vertex of the parabola whose equation is y = 3x^2 + 9x?

a) -3
b) -1 1/2
c) -2/3

Answer 1

I got -3/2.

Answer 2

\(-\frac{b}{2a}\) which in your case is \(-\frac{9}{2\times 3}\)

Answer 3

so yeah, \(-\frac{3}{2}\)