Ta có : \(A=\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3.45^6}\)
=\(\frac{3^6.5^4.3^8-3^{13}.5^{13}.5^{-9}}{3^{12}.5^6+5^6.3^{12}}\)
=\(\frac{3^{14}.5^4-3^{13}.5^4}{3^{12}.5^6+5^6.3^{12}}=\frac{3^{13}.5^4.\left(3-1\right)}{5^6.3^{12}.\left(1+1\right)}=\frac{3}{5^2}=\frac{3}{25}\)