Question

化简求值b/(a-b)-b³/(a³-2a²b+ab²)÷(ab+b²

Answer 1

原式=b/(a-b)-b³/a(a-b)²÷[b(a+b)/(a+b)(a-b)]}

=b/(a-b)-b³/a(a-b)²×[(a-b)/b]

=b/(a-b)-b²/a(a-b)

=(ab-b²)/a(a-b)

=b/a

当a=-2,b=3时

原式=b/a=3/(-2)=-3/2