I believe it is 11.
If -3=x in f(x) then plugging that into 5-2(x) would be 5-2(-3).
When you solve that, it comes out to 11, because -2 times -3 is 6.
5+6= 11
Let me know if it is right because if not there is another way to do it. (Has a different answer) comment down below.