(5x+1)/(x-1)(x-2)=A/(x-1)+11/(x-2)
(5x+1)/(x-1)(x-2)=[A(x-2)+11(x-1)]/(x-1)(x-2)=[(A+11)x-(2A+11)]/(x-1)(x-2)
A+11=5
2A+11=-1
A=-6