\(C=\frac{2^{19}.27^3-15.4^9.9^4}{6^9.2^{10}-12^{10}}\)
\(C=\frac{2^{19}.\left(3^3\right)^3-3.5.\left(2^2\right)^9.\left(3^2\right)^4}{\left(2.3\right)^9.2^{10}-\left(3.2^2\right)^{10}}\)
\(C=\frac{2^{19}.3^9-3.5.2^{18}.3^8}{2^9.3^9.2^{10}-3^{10}.2^{20}}\)
\(C=\frac{2^{19}.3^9-3^9.2^{18}.5}{2^{19}.3^9-3^{10}.2^{20}}\)
\(C=\frac{2^{18}.3^9\left(2-5\right)}{2^{18}.3^9\left(2-3.2^2\right)}\)
\(C=\frac{-3}{-10}=\frac{3}{10}\)
\(C=\frac{2^{19}.27^3-15.4^9.9^4}{6^9.2^{10}-12^{10}}\)
\(\Rightarrow C=\frac{2^{19}.\left(3^3\right)^3-3.5.\left(2^2\right)^9.\left(3^2\right)^4}{\left(2.3\right)^9.2^{10}-3^{10}.2^{20}}\)
\(\Rightarrow C=\frac{2^{19}.3^9-3.5.2^{18}.3^8}{2^{19}.3^9-3^{10}.2^{20}}\)
\(\Rightarrow C=\frac{-3}{-10}\)