Tính nhanh nếu có thể:
b) \(\dfrac{5^4.20^4}{25^5.4^5}\)
Tính nhanh nếu có thể:
a) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)
b) \(\dfrac{5^4.20^4}{25^5.4^5}\)
c) \(\dfrac{8^{10}+4^{10}}{8^4+4^{11}}\)
a) \(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\)
\(=\left(\frac{15}{12}-\frac{3}{12}\right)+\left(\frac{5}{13}-\frac{18}{13}\right)\)
\(=1+\left(-1\right)\)
\(=0\)
b) \(\frac{5^4.20^4}{25^5.4^5}=\frac{\left(20.5\right)^4}{\left(25.4\right)^5}=\frac{100^4}{100^5}=\frac{1}{100}\)
c) \(\frac{8^{10}+4^{10}}{8^4+4^{11}}=\frac{\left(2^3\right)^{10}+\left(2^2\right)^{10}}{\left(2^3\right)^4+\left(2^2\right)^{11}}=\frac{2^{30}+2^{20}}{2^{12}+2^{22}}=\frac{2^{12}.\left(2^{18}+2^8\right)}{2^{12}.\left(1+2^{10}\right)}=\frac{2^{18}+2^8}{1+2^{10}}=256\)
Tính nhanh nếu có thể:
a) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)
b) \(\dfrac{5^4.20^4}{25^5.4^5}\)
c) \(\dfrac{8^{10}+4^{10}}{8^4+4^{11}}\)
a) \(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\)
\(=\left(\dfrac{15}{12}-\dfrac{3}{12}\right)+\left(\dfrac{5}{13}-\dfrac{18}{13}\right)\)
\(=\dfrac{12}{12}+\dfrac{-13}{13}\)
\(=1-1\)
\(=0\)
b) \(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}\)
\(=\dfrac{100^4}{100^5}\)
\(=\dfrac{1}{100}\)
\(\dfrac{5^4.20^4}{25^5.4^5}\)
\(\dfrac{5^4.20^4}{25^5.4^5}\)
\(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{25^2\left(5.4\right)^4}{25^5.4^5}=\dfrac{1.5^4.4^4}{25^3.4^5}=\dfrac{25^2.1}{25^3.4}=\dfrac{1}{25.4}=\dfrac{1}{100}\)
\(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{5^4.\left(5.4\right)^4}{\left(5^2\right)^5.4^5}=\dfrac{5^4.5^4.4^4}{5^{10}.4^5}=\dfrac{5^8.4^8}{5^{10}.4^5}=\dfrac{1.1}{5^2.4}=\dfrac{1}{100}\)
Tính: \(\dfrac{5^4.20^4}{25^5.4^5}\)
Ta có:
\(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{5^4.5^4.4^4}{\left(5^2\right)^5.4^5}=\dfrac{5^8.4^4}{5^{10}.4^5}=\dfrac{1}{5^2.4}=\dfrac{1}{25.4}=\dfrac{1}{100}=0,01\)
\(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{5^4.\left(4.5\right)^4}{\left(5.5\right)^5.4^5}=\dfrac{5^4.4^4.5^4}{5^5.5^5.4^5}=\dfrac{1}{5.5.4}=\dfrac{1}{100}\)
\(\dfrac{5^4.20^4}{25^5.4^5}=\dfrac{5^4.\left(5.4\right)^4}{\left(5^2\right)^5.4^5}=\dfrac{5^4.5^4.4^4}{5^{10}.4^5}=\dfrac{5^8.4^4}{5^8.5^2.4.4^4}=\dfrac{1}{100}\)
tính
\(\dfrac{5^4.20^4}{25^5.4^5}\)
\(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}=\dfrac{\left(5\cdot20\right)^4}{\left(25\cdot4\right)^5}=\dfrac{100^4}{100^5}=\dfrac{1}{100}\)
Tính: \(\dfrac{5^4.20^4}{25^5.4^5}\)
\(\dfrac{4^5.9^4}{8^3.27^3}\);\(\dfrac{4^{20}.3^{35}}{2^{37}.27^{12}}\)\(;\dfrac{5^4.20^4}{25^5.4^5};\dfrac{2^{15}.9^4}{6^6.8^3}\)
\(\dfrac{4^5\cdot9^4}{8^3\cdot27^3}=\dfrac{\left(2^2\right)^5\cdot\left(3^2\right)^4}{\left(2^3\right)^3\cdot\left(3^3\right)^3}=\dfrac{2^{10}\cdot3^8}{2^9\cdot3^9}=\dfrac{2}{3}\)
\(\dfrac{4^{20}\cdot3^{35}}{2^{37}\cdot27^{12}}=\dfrac{\left(2^2\right)^{20}\cdot3^{35}}{2^{37}\cdot\left(3^3\right)^{12}}=\dfrac{2^{40}\cdot3^{35}}{2^{37}\cdot3^{36}}=\dfrac{2^3}{3}\)
\(\dfrac{5^4\cdot20^4}{25^5\cdot4^5}=\dfrac{5^4\cdot5^4\cdot4^4}{5^5\cdot5^5\cdot4^5}=\dfrac{1}{5^2\cdot4}=\dfrac{1}{100}\)
\(\dfrac{2^{15}\cdot9^4}{6^6\cdot8^3}=\dfrac{2^{15}\cdot\left(3^2\right)^4}{2^6\cdot3^6\cdot\left(2^3\right)^3}=\dfrac{2^{15}\cdot3^8}{2^6\cdot3^6\cdot2^9}=3^2\)
tính
5^4.20^4/25^5.4^5
\(\frac{5^4.20^4}{25^5.4^5}=\frac{5^4.\left(4.5\right)^4}{\left(5.5\right)^5.4^5}=\frac{5^4.4^4.5^4}{5^5.5^5.4^5}=\frac{5^8.4^4}{5^8.5^2.4^4.4}=\frac{1}{5^2.4}=\frac{1}{100}\)