[(-1/3)^1999].(3^2000).[(3/4)^99].[(1/3)^100]
=-(3)^(-1999).(3^2000).[(3^99). (2^(-198) )] .[3^(-100)]
=-3^(-1999+2000+99-100) . 2^(-198)
=-3^0 . 2^(-198)
=-(2^(-198))
(-1/3)^1999*3^2000*(3/4)^99*(4/3)^100=-(1/3*3)^1999*3*(3/4*4/3)^99*4/3=-1*3*1*4/3=-4