1. The problem statement, all variables and given/known data (x^3+4)/((x^2-1)(x^2+3x+2)) 2. Relevant equations 3. The attempt at a solution Try separating them into Ax+B and Cx+D, then expand until (A+C)x3+(3A+B+D)x2+(2A+3B-C)x+(2B-D) then, I was stuck. I can't find any value for A,B,C or D. Is my attempt correct or is there other way to solve it?