\(\frac{2^{19}.27^3+15.4^9.9^4}{6^9.2^{10}+12^{10}}\)
\(=\frac{2^{19}.3^9+3.5.2^{18}.3^8}{2^9.3^9.2^{10}+2^{20}.3^{10}}\)
\(=\frac{2^{19}.3^9+2^{18}.3^9.5}{2^{19}.3^9+2^{19}.2.3^9.3}\)
\(=\frac{2^{18}.3^9.\left(2+5\right)}{2^{19}.3^9.\left(1+6\right)}\)
\(=\frac{7}{2.7}\)
\(=\frac{1}{2}\)