Question

What are the vertex and x-intercepts of the graph of the function below?

y =(x + 4)(x + 2)
A. Vertex: (1, -5); Intercepts: x = -4, 2
B. Vertex: (1, -9); Intercepts: x = 4, -2
C. Vertex: (-4, 2); Intercepts: x = 3, -3
D. Vertex: (-3, -1); Intercepts: x = -4, -2

Answer 1

The x intercepts occur where x = 0, and in your case x + 4 = 0, and x + 2 = 0. So solving those for x, you get x = -4 (that's one x intercept) and x = -2 (that's the other x intercept).

Answer 2

The vertex is in between these with an x value of -3. Which vertex above shows us an x value of -3? With -4 and -2 as x intercepts?

Answer 3

D is your answer.