计算题：1.1/a+1—2/1-a² 2.x/x-y—y/x+y

计算题：1.1/a+1—2/1-a² 2.x/x-y—y/x+y
计算题：1.1/a+1—2/1-a² 2.x/x-y—y/x+y

计算题：1.1/a+1—2/1-a² 2.x/x-y—y/x+y
原式=(a-1)/(a+1)(a-1)+2/(a+1)(a-1)
=(a-1+2)/(a+1)(a-1)
=(a+1)/(a+1)(a-1)
=1/(a-1)
原式=(x²+xy-xy+y²)/(x+y)(x-y)
=(x²+y²)/(x²-y²)

俊狼猎英团队为您
1/(a+1)-2/(1-a^2)
=[(1-a)-2]/[(1+a)(1-a)]
=-(1+a)/[(1-a)(1+a)]
=-1/(1-a)
=1/(a-1)

1.
1/a+1—2/1-a²
=(1-a)/(1-a)(1+a)-2/(1-a)(1+a)
=-(a+1)/(1-a)(1+a)
=-1/(1-a)
=1/(a-1)

2.
x/x-y—y/x+y
=x(x+y)/(x-y)(x+y)-y(x-y)/(x-y)(x+y)
=(x²+y²)/(x-y)(x+y)