помогите)) нужно упростить))

$a^{\frac{3}{4}}b^{-\frac{11}{3}}:(a^{\frac{7}{8}}b^{\frac{5}{6}})=a^{\frac{3}{4}-\frac{7}{8}}b^{-\frac{11}{3}-\frac{5}{6}}=a^{-\frac{1}{8}}b^{-\frac{27}{6}}=\frac{1}{a^{\frac{1}{8}}b^{\frac{27}{6}}}$

$27^{\frac{1}{3}}-25^{-\frac{1}{2}}+16^{\frac{3}{4}}-27^{1\frac{1}{3}}=(3^3)^{\frac{1}{3}}-(5^2)^{-\frac{1}{2}}+(2^4)^{\frac{3}{4}}-(3^3)^{\frac{4}{3}}= \\ =3-5^{-1}+2^3-3^4=3-\frac{1}{5}+8-81=-70\frac{1}{5}$