Question

化简分式（x/【x-1】-x/【x²-1】）·x+1/x²,并选一个你认为合适的整数x代入求值.

Answer 1

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

={(x^2+x-x)/[(x-1)(x+1)]}*(x+1)/x^2.

=1/(x-1)

取x=2,则原式=1/(2-1)=1.