Question

当x=3时，求X的平方-X-2分之3x+2+（1-X+1分之1）除以（1+X-1分之1）的值

题我打的乱，做起来还好

Answer 1

(3x+2)/(x²-x-2)+[1-1/(x+1)]÷[1+1/(x-1)]
=(3x+2)/(x-2)(x+1)+[(x+1-1)/(x+1)]÷[(x-1+1)/(x-1)]
=(3x+2)/(x-2)(x+1)+x/(x+1)*(x-1)/x

=(3x+2)/(x-2)(x+1)+(x-1)/(x+1)

=[3x+2+(x-1)(x-2)]/(x-2)(x+1)
=(x²+4)/(x-2)(x+1)
=(9+4)/(3-2)(3+1)
=13/4