2的2a-1次方×2的3b-2次方×2的a+3c次方
=2的(2a-1+3b-2+a+3c)次方
=2的(3a+3b+3c-3)次方
=2的3(a+b+c-1)次方
=2的3(2-1)次方
=2的3次方
=8