The following function is quadratic.

f (x) = (x+4) (x-6)

What is the value of the positive x-intercept of the graph of the related equation y = (x+4) (x-6) ?

Answer: 6

You replace f (x) or y with 0, and then solve for x

y = (x+4) (x-6)

(x+4) (x-6) = y

(x+4) (x-6) = 0

x+4 = 0 or x-6 = 0 ... zero product property

x = - 4 or x = 6

The x intercepts are - 4 and 6. In this case, only 6 is the positive x intercept.

side note: The term "root" is another way to say "x-intercept"