E(x)=[(2/(x+1)+x/(1-x²) -(3x+6)/(x²+x-2)] :1/(1-x) = (2x+5)/(x+1)
E(x)=[(2/(x+1)+x/(1-x²) -(3x+6)/(x²+x-2)] :1/(1-x) =
=[(2/(x+1)-x/(x-1)(x+1) -3(x+2)/(x-1)(x+2)] ×(1-x) =
=[(2/(x+1)-x/(x-1)(x+1) -3/(x-1)] ×(1-x) =
=(2x-2-x-3x-3)/(x+1)(x-1) ×(1-x) =
=(-2x-5)/(x+1)(x-1) ×(1-x) =
=(2x+5)/(x+1)(1-x) ×(1-x) =
=(2x+5)/(x+1)