Question

Which of the following functions best describes this graph?

A. y = x^2 - 8x +18
B. y = (x+4)(x+5)
C. y = x^2 -9x +20
D. y = (x-3)(x+4)​

Answer 1

C

Explanation:

Looking at the graph, we can see the roots at two points

these are points x = 4 and x = 5

This can be written in their linear forms as;

x-4 and x-5

Finding the products of both, we have

x(x-5) -4(x-5)

= x^2 -5x -4x + 20

= x^2 - 9x + 20