Question

先化简,要过程(x-1分之1-x+1分之1)除以2x平方-2分之x,然后从根号2,1,-1中选取一个认为合适的数

Answer 1

(x-1分之1-x+1分之1)除以2x平方-2分之x

=[1/(x-1)-1/(x+1)]÷x/2(x²-1)

=(x+1-x+1)/(x²-1)÷x/2(x²-1)

=2*2/x

=4/x x=1

=4/1

=4