\(P=\dfrac{8^4.3^5-4^6.9^3}{4^6.9^3+4^8.3^5}\)
\(=\dfrac{\left(2^3\right)^4.3^5-\left(2^2\right)^6.\left(3^2\right)^3}{\left(2^2\right)^6.\left(3^2\right)^3+\left(2^2\right)^8.3^5}\)
\(=\dfrac{2^{12}.3^5-2^{12}.3^6}{2^{12}.3^6+2^{16}.3^5}\)
\(=\dfrac{2^{12}\left(3^5-3^6\right)}{2^{12}.2^4\left(3^3+3^5\right)}\)
\(=\dfrac{\left(-3\right)}{8.3^8}\)
\(=\dfrac{-1}{8.3^7}\)
\(P=\dfrac{8^4.3^5-4^6.9^3}{4^6.9^3+4^8.3^5}=\dfrac{2^{12}.3^5-2^{12}.3^6}{2^{12}.3^6+2^{16}.3^5}=\dfrac{2^{12}.3^5\left(1-3\right)}{2^{12}.3^5\left(3+2^4\right)}=\dfrac{-2}{19}\)Nguyễn Thanh Hằng xem lại kết quả đi
