It is asking you to substitute or plug in the values.
Example:
Evaluate 3r(s+3) if r = -3 and s = 5
See that r? It means that you put in -3 in place of the r, and you put 5 in place of the s so it looks like this:
3*-3(5+3)
Now solve that using order of operations and you should get
-9*(5+3) (don't forget that your'e distributing here FIRST then add)
-45+-27
-72
That's how you solve an expression like that. This is only an EXAMPLE. Hope it helped.
