(a-2)分之a - (a二次方-2a)分之2a - a分之2=a²/a(a-2) - 2a/a(a-2) - 2(a-2)/a(a-2)=(a²-2a-2a+4)/a(a-2)=(a-2)²/a(a-2)=(a-2)/aa=2分之3原式=(a-2)/a=(2分之3-2)/2分之3= -3分之1...