A= 4^5.9^4-2.6^9
2^10.3^8+6^8.20
B= 4^6.9^5+6^9.120
8^4.3^12-6^11
Tính nhanh :
f) \(\frac{2.6^9-2^5.18^4}{2^6.6^8}\)
h) \(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
Thực hiện phép tính:
a. A=\(\dfrac{5^2.6^{11}.16^2+6^2.12^6.15^2}{2.6^{12}.10^4-81^2.960^3}\)
b. B=\(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
a: \(A=\dfrac{5^2\cdot3^{11}\cdot2^{11}\cdot2^8+3^2\cdot2^2\cdot2^{12}\cdot3^6\cdot3^2\cdot5^2}{2\cdot2^{12}\cdot3^{12}\cdot2^4\cdot5^4-3^8\cdot960^3}\)
\(=\dfrac{5^2\cdot3^{11}\cdot2^{19}+3^{10}\cdot2^{14}\cdot5^2}{2^{17}\cdot3^{12}\cdot5^4-3^{11}\cdot2^{18}\cdot5^3}\)
\(=\dfrac{5^2\cdot2^{14}\cdot3^{10}\left(3\cdot2^5+1\right)}{2^{17}\cdot3^{11}\cdot5^3\left(3\cdot5-2\right)}=\dfrac{1}{5}\cdot\dfrac{1}{8}\cdot\dfrac{1}{10}\cdot\dfrac{97}{13}=\dfrac{97}{5200}\)
b: \(B=\dfrac{2^{12}\cdot3^{10}+2^9\cdot3^9\cdot2^3\cdot3\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}\)
\(=\dfrac{2^{12}\cdot3^{10}\cdot\left(1+5\right)}{2^{11}\cdot3^{11}\left(2\cdot3-1\right)}=\dfrac{2}{3}\cdot\dfrac{6}{5}=\dfrac{12}{15}=\dfrac{4}{5}\)
tính giá trị các biểu thức sau:
a) \(A=\dfrac{2^{15}.9^4}{6^6.8^3}\)
b) \(B=\dfrac{4^6.9^5+6^9.120}{-8^4.3^{12}-6^{11}}\)
c) \(C=\dfrac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
có bn nào lm dc thì lm giúp mk vs nha mai mk nộp bài r
a)\(\dfrac{2^{15}.3^8}{2^6.3^6.2^9}\)\(\dfrac{ }{ }\)=\(^{3^2}\)=9
b)\(\dfrac{2^{12}.3^{10}+2^9.3^9.2^3.15}{-2^{12}.3^{12}-2^{11}.3^{11}}\)=\(\dfrac{2^{11}.3^{11}.\left(1+15\right)}{2^{11}.3^{11}\left(-2.3-1\right)}\)
=\(\dfrac{32}{-21}\)
c)\(\dfrac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^8.3^8.2^2.5}\)=\(\dfrac{2^{10}.3^8\left(1-3\right)}{2^{10}.3^8\left(1+5\right)}\)=\(-\dfrac{1}{3}\)
em dựa vào vd \(\dfrac{4^{16}}{2^8}\)= \(\dfrac{\left(2^2\right)^{16}}{2^8}=\dfrac{2^{16\cdot2}}{2^8}=2^4=16\)
tính A = 4^6.9^5+6^9.120/8^4.3^12-6^11
\(\dfrac{-4^6.9^5-6^9.120}{-8^4.3^{12}-6^{11}}\)
\(=\dfrac{-2^{12}\cdot3^{10}-2^{12}\cdot3^{10}\cdot5}{-2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\dfrac{2^{12}\cdot3^{10}\cdot6}{2^{11}\cdot3^{11}\cdot7}=\dfrac{2\cdot6}{3\cdot7}=\dfrac{12}{21}=\dfrac{4}{7}\)
(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: \(A=\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^9.3^9.2^3.3.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)
\(=\dfrac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{11}.3^{11}\left(2.3-1\right)}\)
\(=\dfrac{2^{12}.3^{10}\left(1+5\right)}{2^{11}.3^{11}.5}\)
\(=\dfrac{2^{12}.3^{10}.6}{2^{11}.3^{11}.5}=\dfrac{2.6}{3.5}=\dfrac{4}{5}\)
\(A=\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}=\dfrac{\left(2^2\right)^6.\left(3^2\right)^5+6^9.6.2^2.5}{\left(2^3\right)^4.3^{12}-6^{11}}=\dfrac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}=\dfrac{2^{11}.3^{10}\left(2^1+2^1.5\right)}{2^{11}.3^{10}\left(2^1.3^2-1.3^1\right)}=\dfrac{2+10}{2.9-1.3}=\dfrac{12}{15}=\dfrac{4}{5}\)
C=4^6.9^5+6^9.120:8^4.3^12+6^11
\(4^6.9^5+6^9.120:8^4.3^{12}+6^{11}=\frac{4^6.9^5+6^9.120}{8^4.3^{12}+6^{11}}=\frac{ \left(2^2\right)^6.\left(3^2\right)^5+6^9.6.20}{2^3.3^{12}+6^9.6.6}=\frac{2^{12}.3^{10}+20}{2^3.3^{12}+6}=\frac{2^9+20}{3^2+6}\)
\(\frac{2^9+20}{3^2+6}=\frac{512+20}{9+6}=\frac{532}{15}\)