Calculating a set of input

Hi, I have a formula with variable unknowns, lets say p,q,r.

How do I get the answer giving me the output for different combination of input that I'm inserting?

For example : f(p,q,r):=(34p^9-7q)/r

Calculate when (p=2,q=8,r=7) and (p=3,q=0,r=3) and (p=4,q=1,r=9) and so on...

Please advice. Many thanks