Question

Nina knows that the average of the x-intercepts represents the line of symmetry for a quadratic function through the x-axis. Which equation represents the average of the x-intercepts for f(x) = 4x2 – 24x + 20?

-5-1/2 = -3
-10-2/2 = -4
1+5/2 = 3
2+10/2 = 4

Answer 1

To get the x-intercepts of the function, f(x) = 4x2 – 24x + 20

It has to be equated to zero and the values of x are the x-intercepts. So,
4x2 – 24x + 20 = 0
The resulting equation is a quadratic equation which can be solved by different methods. The solution is
x = 5, 1
The average therefore is:
(1+5/)2 = 3