先化简再求值(X-1分之3-x+1分之1)除以x平方-1分之x,其中x=2分之1

发布时间:2021-02-20 02:42:01

先化简再求值(X-1分之3-x+1分之1)除以x平方-1分之x,其中x=2分之1

网友回答

原式=[ 3/(x-1) -1/(x+1) ]÷ x/(x²-1)=[ 3/(x-1) -1/(x+1) ]×(x²-1)/x=[ 3/(x-1) ]×(x²-1)/x -[ 1/(x+1)]×(x²-1)/x=3(x+1)/x -(x-1)/x=(3x+3-x+1)/x=(2x+4)/x=2(x+2)/x当x=1/2时原式=2(1/2 ...
======以下答案可供参考======
供参考答案1:
[3/(x-1)﹣1/(x+1)]/[x/(x²-1)]
=[3(x+1)/(x+1)(x-1)﹣(x-1)/(x+1)(x-1)]/[x/(x+1)(x-1)]
=[(3x+3-x+1)/(x+1)(x-1)]×[(x+1)(x-1)/x]
=(2x+4)/x
=2+4/x
=2+4×2
=10供参考答案2:
=(3/x-1 -1/x-1)*(x-1)(x+1)/x=2/x-1*(x-1)(x+1)/x=2(x+1)/x 2(1/2+1)*2=5
供参考答案3:
x=2+根号3分之1x=(2-根号3)x-1分之2+x平方-1分之2-x除以x平方-2x-3分之x平方-4x+4=2/(x-1)+(2-x)/(x^2-1)  /  ((x-2)^2/(x-3)(x+1))=2/(x-1)-(x-2)/(x-1)(x+1)  *  ((x-3)(x+1)/(x-2)^2)=2/(x-1)-  (x-3)/(x-2)(x-1)=(2(x-2)- (x-3))/(x-2)(x-1)=(2x-4-x+3)/(x-2)(x-1)=(x-1)/(x-2)(x-1)=1/(x-2)=1/((2-√3-2)=-√3/3
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