Question

which function has real zeros at $x = 3$ and $x = 7$?$\bigcirc$ $f(x) = x^2 + 4x - 21LXB0\bigcirc$ $f(x) = x^2 - 10x + 21$$\bigcirc$ $f(x) = x^2 - 10x - 21$

Explanation:

Step1: Use zero-product property

If $x=3$ and $x=7$ are zeros, then $(x-3)$ and $(x-7)$ are factors.

Step2: Multiply the factors

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

Step3: Expand the product

$$f(x)=x^2 -7x -3x +21 = x^2 -10x +21$$

Answer:

C. $f(x) = x^2 - 10x + 21$