3a^-2乘以b乘以2ab^-2
要过程的!
3a^-2*b*2ab^-2
=(3*2)*(a^-2*a^1)*(b^1*b^-2)
=(3*2)*a^(-2+1)*b^(1-2)
=6a^-1b^-1
=6/(ab)