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?

Answer 1

c

Explanation:

Answer 2

number of x intercepts in this equation is 2 because max power in the function is 2. number of x intercepts is determined by "highest power".

let x1 represent first x intercept and
let x2 represent second x intercept

Formula for finding average of x intercepts is logicaly:
Avg = (x1 + x2)/2

we want to find x1 and x2
4x^2 - 24x + 20 = 0
x^2 - 6x + 5 = 0


`x = (6 +- √(6^2 - 4*1*5) )/(2*1)`
x1 = 5
x2 = 1

Avg = 3