关于分式的题(x-1)[1-(x+1)/(x-1/x)]

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关于分式的题(x-1)[1-(x+1)/(x-1/x)]

关于分式的题(x-1)[1-(x+1)/(x-1/x)]
关于分式的题
(x-1)[1-(x+1)/(x-1/x)]

关于分式的题(x-1)[1-(x+1)/(x-1/x)]
(X-1)[1-(X+1)/(X-1/X)]
= (X-1)[ 1- (X+1) (X/(X²-1)]
= (X-1)[1-(X²+X)/(X²-1)]
= (X-1){(X²-1-X²-X)/(X²-1)
= (X-1){(-X-1)/[(X+1)(X-1)]}
= (-(X+1) {(X-1))/[(X+1)(X-1)]}
= -1
如果写在作业本或者试卷上,就不用写大括号的了;我是因为这里写分数线写不了,才加了个大括号上去,方便看

(x-1)[1-(x+1)/(x-1/x)]
=(x-1)[1-(x+1)/(x+1)(x-1)/x]
=(x-1)[1-(x+1)*x/(x+1)(x-1)]
=(x-1)[1-x/x-1]
=(x-1)*1-(x-1)*(x/x-1)
=(x-1)-x
=-1

原式=(x-1)[1-(x+1)*(x/x-1)]
=(x-1)[1-(x+1)x/(x-1)]
=(x-1)-(x+1)x 【把(x-1)乘进去中括号的每一项
=x-1-x²-x
=-x²-1

(x-1)[1-(x+1)/(x-1/x)]
=(x-1)[1-(x+1)/(x+1)(x-1)/x]
=(x-1)[1-(x+1)*x/(x+1)(x-1)]
=(x-1)[1-x/x-1]
=(x-1)*1-(x-1)*(x/x-1)
=(x-1)-x
=-1
这个够不够详细?

(x-1)[1-(x+1)/(x-1/x)]
=(x-1)[(x-1/x-x-1)/(x-1/x)]
=(x-1)[(-1/x-1)/(x-1/x)]
=(x-1)[(-x-1)/(x^2-1)]
=-(x^2-1)/(x^2-1)
=-1