Question

Can someone help me please to see if I did this correctly ?
Suppose that the functions r and s are defined for all real numbers x as follows.

r(x)=2x+2
s(x)=x-2
Write the expressions for (s-r)(x) and (s+r)(x) and evaluate (s*r)(-2)

(s-r)(x)= x-5-(2x+2)
(s+r)(x)=x-5+(2x+2)
(s*r)(-2)=

I'm having a little trouble on the last part on how to solve it.