原式=(x³+3)/(x²-1)-(x+1)²/(x²-1)+(x²-1)/(x²-1)
=[x³+3-(x²+2x+1)+(x²-1)] /(x²-1)
=(x³-2x+1)/(x²-1)
=[x(x²-1)-(x-1)] /(x²-1)
=x - 1/(x+1)
原式=(x³+3)/(x²-1)-(x+1)²/(x²-1)+(x²-1)/(x²-1)
=[x³+3-(x²+2x+1)+(x²-1)] /(x²-1)
=(x³-2x+1)/(x²-1)
=[x(x²-1)-(x-1)] /(x²-1)
=x - 1/(x+1)