化简求值 X/X+2 - X2+2X+1/X+2 ÷ X2-1/X-2 其中X=√3-2

问题描述:

化简求值 X/X+2 - X2+2X+1/X+2 ÷ X2-1/X-2 其中X=√3-2

X/X+2 - X2+2X+1/X+2 ÷ X2-1/X-2
=[x/(x+2)]-[(x+1)^2/(x+2)]*{(x-2)/[(x+1)(x-1)]}
=[x/(x+2)]-{(x+1)(x-2)/[(x+2)*(x-1)]}
={1/(x+2)}*{x-[(x^2-x-2)/(x-1)]}
={1/(x+2)}*{2/(x-1)}
=2/[(x+2)(x-1)]
=2/[√3*(√3-3)]
=-(1+√3)/3
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