\(=\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(=\dfrac{2^{12}.3^{10}+3^9.2^9.3.2^3.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)
\(=\dfrac{2^{12}.3^{10}\left(1+5\right)}{2^{11}3^{11}\left(6-1\right)}\)
\(=\dfrac{2^{13}3^{11}}{2^{11}.3^{11}.5}\)
\(=\dfrac{2^2}{5}=\dfrac{4}{5}\)