limlimitsxto32x2+x−21x−3
2x2+x−21=2x2−6x+7x−21 (by factorizing)
= (2x+7)(x−3)
∴limlimitsxto32x2+x−21x−3≡limlimitsxto3(2x+7)(x−3)x−3
limlimitsxto3(2x+7)=2(3)+7=13