\(A=\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
\(=\frac{2^{10}.3^8-2.\left(2.3\right)^9}{2^{10}.3^8+\left(2.3\right)^8.\left(2^2.5\right)}\)
\(=\frac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^{10}.3^8.5}\)
\(=\frac{2^{10}.3^8\left(1-3\right)}{2^{10}.3^8\left(1+5\right)}\)
\(=\frac{-2}{6}\)
\(=\frac{-1}{3}\)
Vậy \(A=\frac{-1}{3}\)