A/(3+x) + B/(1-x) + C/(2x+1) = (9x^2 + 43x + 8)/(3+x)(1-x)(2x+1)So... A(1-x)(2x+1) + B(3+x)(2x+1) + C(3+x)(1-x) = (9x^2 + 43x + 8)Insert x=1Equation becomes 12B = 60 so B = 5.Then insert x=-3Equation becomes -20A = -40 so A = 2Then insert x = -0.5Equation becomes 3.75C = -11.25 so C = -3.
So answer is 2/(3+x) + 5/(1-x) - 3(2x+1).