①原式
=(x-1/x²-1)+(1/x²-1)-(x+1/x²-1)
=(x-1+1-x-1)/(x²-1)
=-1/x²-1
②原式
=(1/x+1)-(x+2)/(x+1)(x-1) × (x-1)²/(x+2)²
=(1/x+1)-(x-1)/(x+1)(x+2)
=(x+2)/(x+1)(x+2) - (x-1)/(x+1)(x+2)
=(x+2-x+1)/(x²+3x+2)
=3/(x²+3x+2)
①原式
=(x-1/x²-1)+(1/x²-1)-(x+1/x²-1)
=(x-1+1-x-1)/(x²-1)
=-1/x²-1
②原式
=(1/x+1)-(x+2)/(x+1)(x-1) × (x-1)²/(x+2)²
=(1/x+1)-(x-1)/(x+1)(x+2)
=(x+2)/(x+1)(x+2) - (x-1)/(x+1)(x+2)
=(x+2-x+1)/(x²+3x+2)
=3/(x²+3x+2)