$3a^{-3}\ast 4a^{-4}=12a^{-3-4}=12a^{-7}$

$\frac{10b^{-4}}{15b^{-5}}=\frac{2}{3b^{-1}}=\frac{2}{3}b$

$(2c^{-6}{)}^4=2^4{c}^{-6\ast 4}=16c^{-24}$

$m^{-2}n\ast m{n}^{-2}=m^{-2+1}{n}^{1-2}=m^{-1}{n}^{-1}$

$ab{c}^{-1}\ast a{b}^{-1}c=a^{1+1}{b}^{1-1}{c}^{-1+1}=a^2{b}^0{c}^0=a^2$

$\frac{k{p}^{-6}}{k^4{p}^4}=\frac{1}{k^3{p}^{4+6}}=\frac{1}{k^3{p}^{10}}$

$(c^{-6}{d}^2{)}^{-7}=c^{-6\ast (-7)}{d}^{2\ast (-7)}=c^{42}{d}^{-14}$

$\frac{1}{3}{a}^{-3}{b}^{-6}\ast \frac{6}{7}{a}^7{b}^4=(\frac{1}{3}\ast \frac{6}{7})a^{-3+7}{b}^{-6\ast 4}=\frac{2}{7}{a}^4{b}^{-2}$

$0,2c^{-3}{d}^5\ast 1,5c^{-2}{d}^{-5}=(0,2\ast 1,5)c^{-3-2}{d}^{5-5}=0,3c^{-5}{d}^0=0,3c^{-5}$

$4x^8\ast (-3x^{-2}{y}^4{)}^{-2}=4x^8\ast \frac{1}{(-3x^{-2}{y}^4{)}^2}=4x^8\ast \frac{1}{(-3{)}^2{x}^{-2\ast 2}{y}^{4\ast 2}}=4x^8\ast \frac{1}{9x^{-4}{y}^8}=\frac{4x^{8-(-4)}}{9y^8}=\frac{4x^{8+4}}{9y^8}=\frac{4x^{12}}{9y^8}$

$\frac{13m^{-10}}{12n^{-8}}\ast \frac{27n}{26m^2}=\frac{m^{-10}}{4n^{-8}}\ast \frac{9n}{2m^2}=\frac{n^8}{4m^{10}}\ast \frac{9n}{2m^2}=\frac{9n^{8+1}}{8m^{10+2}}=\frac{9n^9}{8m^{12}}$

$\frac{18p^{-6}{k}^2}{7}:\frac{15k^{-2}}{p^6}=\frac{18p^{-6}{k}^2}{7}\ast \frac{p^6}{15k^{-2}}=\frac{18k^2}{7p^6}\ast \frac{k^2{p}^6}{15}=\frac{6k^2}{7}\ast \frac{k^2}{5}=\frac{6k^4}{35}$