:[(x+1)/(x²-1)]×(x-3)
=(x+1)/(x+1)(x-1)×(x-3)
=1/(x-1)×(x-3)
=(x-3)/(x-1)
b/a+a/b=(a²+b²)/ab=[(a²+2ab+b²)-2ab]/ab=[(a+b)²-2ab]/ab=(4+2)/(-1)=-6
:[(x+1)/(x²-1)]×(x-3)
=(x+1)/(x+1)(x-1)×(x-3)
=1/(x-1)×(x-3)
=(x-3)/(x-1)
b/a+a/b=(a²+b²)/ab=[(a²+2ab+b²)-2ab]/ab=[(a+b)²-2ab]/ab=(4+2)/(-1)=-6