Question

当x=-2时,求（x+1）分之1-（x平方-1）分之（x+3）除以（x平方-2x+1)分之x平方+4x+3）

Answer 1

原式=1/(x+1)-(x+3)/(x+1)(x-1)×(x-1)²/(x+1)(x+3)

=(x+1)/(x+1)²-(x-1)/(x+1)²

=(x+1-x+1)/(x+1)²

=2/(x+1)²

=2/(-2+1)²

=2