x+2分之x-x+2分之x平方+2x+1除以x-1分之x平方-1
=[x/(x+2)-(x²+2x+1)/(x+2)]÷(x²-1)/(x-1)
=[(x-x²-2x-1)/(x+2)]÷(x+1)
=(-x²-x-1)/(x+2)(x+1)
=(-x²-x-1)/(x²+3x+2) 其中x=根号3
=[-(√3)²-√3-1)]/[(√3)²+3*√3+2]
=(-4-√3)/(5+3√3)
=(-4-√3)(5-3√3)/(5+3√3)(5-3√3)
=(-20-5√3+12√3+9)/(25-27)
=(-11+7√3)/(-2)
=(11-7√3)/2