thanks again for the help everyone

Answer:
[tex]\sf{ (z-7)(z-2)}[/tex]
explanation:
[tex]\sf z^2 - 9z + 14[/tex]
break down, (7 * 2) = 14
[tex]\sf z^2 - 7z - 2z + 14[/tex]
collect in parenthesis
[tex]\sf z ( z - 7 ) -2(z - 7)[/tex]
collect in groups
[tex]\sf{ (z-7)(z-2)}[/tex]