limx→11−x−131−x−23
limx→1−(x−13−1)−(x−23−1)
=limx→1x−13−1−13x−23−1−23
=limx→1x−13−1−13x−23−1−23x−1
[Dividing numerator and drominator by x-1]
=(−13)(1)−13−1(−23)(1)−23−1
[limx→axn−anx−a=an−1,n→Q]
=13×32=12