Question

化简求值x²-2x分之x²-1+2x-x²分之x-1,其中x=3

Answer 1

=(x²-1)/(x²-2x)-(x-1)/(x²-2x)

=(x²-1-x+1)/(x²-2x)

=(x²-x)/(x²-2x)

=x(x-1)/x(x-2)

=(x-1)/(x-2)

当x=3时

原式=(3-1)/(3-2)=2