lim【x→0】(e^3x-e^x)ln(1+x)/(1-cox)
=lim【x→0】[】(e^3x-e^x)]x/(x²/2)
=2lim【x→0】[(e^3x-e^x)]/x
=2lim【x→0】[(3e^3x-e^x)]/1
=2[3-1]=4