6ab^2*(-1/3ab^2)/2a*(-ab^2)
=-2a²b^4/(-2a²b²)
=b²
（m^3n+1/2mn^2)/1/3mn
=mn(m²+1/2n)/(1/3mn)
=3(m²+1/2n)
=3m²+3/2n
(根号3）^0-(-1/2)^-3+(-2)^3
=1-(-2)³+(-2)³
=1