The expression for (r-s)(x) is found by subtracting s from r. That difference is

. The expression for (r+s)(x) is found by adding them, which is

. Now we are told to evaluate (r*s)(x) which means they want us to multiply those and state the "new" expression that results.

. There you go!
I don’t know sorry! I might learn that soon so… I’ll see if u can help lately
The answer is going to be around 7 countries
C I think that's it idk I might be wrong sorry if I am
6, 9, 9, 12, 18, 24, 24, 24, 37
37-6= 31