tính A = 4^6.9^5+6^9.120/8^4.3^12-6^11
Tính: 4^6.9^5+6^9.120/-8^4.3^12-6^11
\(\dfrac{-4^6.9^5-6^9.120}{-8^4.3^{12}-6^{11}}\)
\(=\dfrac{-2^{12}\cdot3^{10}-2^{12}\cdot3^{10}\cdot5}{-2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\dfrac{2^{12}\cdot3^{10}\cdot6}{2^{11}\cdot3^{11}\cdot7}=\dfrac{2\cdot6}{3\cdot7}=\dfrac{12}{21}=\dfrac{4}{7}\)
Tính :
\(A=\frac{4^6.9^5+6^9.120}{-8^4.3^{12}-6^{11}}\)
Ta có : \(A=\frac{4^6.9^5+6^9.120}{-8^4.3^{12}-6^{11}}=\frac{\left(2^2\right)^6.\left(3^2\right)^5+2^9.3^9.2^3.3.5}{-\left(2^3\right)^4.3^{12}-2^{11}.3^{11}}\)
\(=\frac{2^{12}.3^{10}+2^{12}.3^{10}.5}{-2^{12}.3^{12}-2^{11}.3^{11}}=\frac{2^{12}.3^{10}\left(1+5\right)}{2^{11}.3^{11}\left(-2.3-1\right)}=\frac{2\left(1+5\right)}{3\left(-6-1\right)}=\frac{2.6}{3.\left(-7\right)}=\frac{-12}{21}\)
(4^6.9^5+6^9.120)/(-6^11-8^4.3^12)
4^6.9^5+6^9.120/-8^4.3^12-6^11
Rút gọn biểu thức: \(A=\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^9.3^9.2^3.3.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{11}.3^{11}\left(2.3-1\right)}\)
\(=\dfrac{2^{12}.3^{10}\left(1+5\right)}{2^{11}.3^{11}.5}\)
\(=\dfrac{2^{12}.3^{10}.6}{2^{11}.3^{11}.5}=\dfrac{2.6}{3.5}=\dfrac{4}{5}\)
\(A=\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}=\dfrac{\left(2^2\right)^6.\left(3^2\right)^5+6^9.6.2^2.5}{\left(2^3\right)^4.3^{12}-6^{11}}=\dfrac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}=\dfrac{2^{11}.3^{10}\left(2^1+2^1.5\right)}{2^{11}.3^{10}\left(2^1.3^2-1.3^1\right)}=\dfrac{2+10}{2.9-1.3}=\dfrac{12}{15}=\dfrac{4}{5}\)
Tính \(\frac{4^6.9^5+6^9.120}{-8^4.3^{12}-6^{11}}\)
\(=-\dfrac{2^{12}\cdot3^{10}+3^9\cdot2^9\cdot2^3\cdot3\cdot5}{2^{12}\cdot3^{12}+2^{11}\cdot3^{11}}\)
\(=-\dfrac{2^{12}\cdot3^{10}+3^{10}\cdot2^{12}\cdot5}{2^{11}\cdot3^{11}\cdot7}\)
\(=-\dfrac{3^{10}\cdot2^{12}\cdot6}{2^{11}\cdot3^{11}\cdot7}=-\dfrac{2}{3}\cdot\dfrac{6}{7}=\dfrac{-12}{21}=-\dfrac{4}{7}\)
C=4^6.9^5+6^9.120:8^4.3^12+6^11
\(4^6.9^5+6^9.120:8^4.3^{12}+6^{11}=\frac{4^6.9^5+6^9.120}{8^4.3^{12}+6^{11}}=\frac{ \left(2^2\right)^6.\left(3^2\right)^5+6^9.6.20}{2^3.3^{12}+6^9.6.6}=\frac{2^{12}.3^{10}+20}{2^3.3^{12}+6}=\frac{2^9+20}{3^2+6}\)
\(\frac{2^9+20}{3^2+6}=\frac{512+20}{9+6}=\frac{532}{15}\)
$\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}$