F (x) = 3x + 2 and g (x) = 2x - 1. Find (g- f(x) I don't understand and its all so confusing, my teacher I like him a lot but he is too smart and sometimes he can forget that and speak so fast than ask you "got all that copied down"? I'm really lost on this please help

I just need the explanation part, and then anything else please! thanks :)