Answer:
x = -3/2 (or x = -1.5)
Step-by-step explanation:
y = 3x² + 9x – 5
by observation, we can see that this quadratic function will produce a parabolic curve (which we know is symmetric about its vertex).
Recall that for a quadratic equation in the from:
y = ax² + bx + c
the x location of the vertex (and also the axis of symmetry) is given by
x = -b/2a
in this case, b = 9 and a = 3
hence
x = -(9) / (2)(3)
x = -9/6
x = -3/2
