1. x≠1, x≠-1
[3x(x+1)+4(x-1)]
/ (x-1)(x+1)=6/(x²-1)
[3x²+7x-4] /
(x²-1)= 6/(x²-1)
[3x²+7x-4-6]
/ (x²-1)=0
[3x²+7x-10]
/(x²-1)=0
3x²+10x-3x-10=x(3x+10)-(3x+10)=(3x+10)(x-1),
(x²-1)=(x-1)(x+1)
[(3x+10)(x-1)]
/ [(x-1)(x+1)]=(3x+10) /(x+1), тогда:
(3x+10) /(x+1)=0
3x+10=0, x=-10/3, Ответ: x=-10/3