Which function has real zeros at x = 3 and x = 7? f(x) = x2 + 4x – 21 f(x) = x2 – 4x – 21 f(x) = x2 – 10x + 21 f(x) = x2 – 10x – 21

f(x) = x2 – 10x + 21

Step-by-step explanation:

If the graphs have zero's at 3 and 7, we can use the zero product property

f(x) = (x-a) (x-b) where a and b are the zero's of the functions

f(x) = (x-3) (x-7)

We can then FOIL the equation

First :x*x = x^2

Outer: -7*x = -7x

Inner: -3x

Last -3*-7 = 21

Add them together

x^2 -7x-3x+21

f(x) = x^2 -10x+21

the answer is a

step-by-step explanation: