Question

先化简再求值 1减(x-1/1-x)的平方除以(x的平方-x+1)/x的立方-2x+1),其中x=1/2

Answer 1

{1-[(X-1)/(1-X)]^}/{(X^-X+1)/(X^3-2X+1)}

={1+[(X-1)/(X-1)]^}/{(X^-X+1)/(X^3-2X+1)}

=4/{(X^-X+1)/(X^3-2X+1)}

=4/{(1/4-1/2+1)/(1/8-2/2+1)}

=4/{(3/4)/(1/8)}

=4/6

=2/3