find the vertex of y=(x+5)(x+4)

Question

I really need help with this equation.it is due tomorrow and i don't understand how to get the answer. 

Answer 1

Two ways of finding the vertex are possible. One is to multiply the factors, complete the square, and then determine the vertex (h, k).

 

A simpler way is to note that -5 and -4 are zeros: (-5, 0), (-4, 0).

The vertex is at the x value half way between - 5 and -4, i.e., -4.5

 

y = (-4.5 + 5)(-4.5 + 4)

y = 1.5(-0.5)

y = -0.75

 

The vertex is (-4.5, -0.75)