Answer:
3, 7
Step-by-step explanation:
"Zeros" means solutions to the equation f(x) = 0. In other words, what are the values of x that make the function's value equal to zero?
This one can be solved by factoring.
[tex]x^2-10x+21=0\\(x-7)(x-3)=0\\x-7=0 \text{ or } x-3=0\\x=7 \text{ or } x=3[/tex]