Question 1105427
4/x+1 + 7/x-1 = 11x+3/(x^2-1)
multiply everything by x^2-1 or (x+1)(x-1)
4(x-1)+7(x+1)=11x+3
4x-4+7x+7=11x+3
This is an identity except where x=-1 and 1, where it is undefined.  
(-oo, -1)U(-1, 1)U(1, oo)