\(\dfrac{4^6.9^5+6^9.120}{8^4.3^2-6^{11}}\)
\(=\dfrac{\left(2^2\right)^6.\left(3^2\right)^5+\left(2.3\right)^9.120}{\left(2^3\right)^4.3^2-\left(2.3\right)^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^9.3^9.120}{2^{12}.3^2-2^{11}.3^{11}}\)
\(=\dfrac{1.3^8+1.1.120}{1.1-4.9}\)
\(=\dfrac{1.6561+120}{1-36}=\dfrac{6681}{-35}\)
Chắc sai đấy!!!! 
\(\dfrac{4^6.9^5+6^9.120}{8^4.3^2-6^{11}}\)
\(=\dfrac{\left(2^2\right)^6.\left(3^2\right)^5+\left(2.3\right)^9.\left(2^3.3.5\right)}{\left(2^3\right)^4.3^2-\left(2.3\right)^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^9.3^9.2^3.3.5}{2^{12}.3^2-2^{11}.3^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^2-2^{11}.3^{11}}\)
\(=\dfrac{2^{12}.3^{10}\left(1+5\right)}{2^{11}.3^2\left(2-3^9\right)}\)
\(=\dfrac{2.3^8.6}{2-3^9}=\dfrac{2.3^8.2.3}{2-3^9}=\dfrac{2^2.3^9}{2-3^9}\)
