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a) \(3,8:\left(2x\right)=\frac{1}{4}:\frac{8}{3}\)
\(=3,8:\left(2x\right)=\frac{3}{32}\)
\(\Rightarrow2x=3,8:\frac{3}{32}=\frac{608}{15}\)
\(\Rightarrow x=\frac{608}{15}:2=\frac{304}{15}\)
b) Yêu cầu j vậy pn?
\(3,8:\left(2x\right)=\frac{1}{4}:\frac{8}{3}\)
\(\Rightarrow2x=\frac{608}{15}\)
\(\Rightarrow x=\frac{304}{15}\)
\(a,\left(\frac{3}{8}+-\frac{3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
= \(\left(-\frac{3}{8}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
= \(\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)
= \(\frac{1}{4}+\frac{1}{2}\)
= \(\frac{3}{4}\)
b)\(-\frac{7}{3}.\frac{5}{9}+\frac{4}{9}.\left(-\frac{3}{7}\right)+\frac{17}{7}\)
=\(-\frac{35}{27}+\left(-\frac{4}{21}\right)+\frac{17}{7}\)
= \(-\frac{35}{27}+\frac{47}{21}\)
= \(\frac{178}{189}\)
c) \(\frac{117}{13}-\left(\frac{2}{5}+\frac{57}{13}\right)\)
= \(\frac{117}{13}-\frac{311}{65}\)
= \(\frac{274}{65}\)
d) \(\frac{2}{3}-0,25:\frac{3}{4}+\frac{5}{8}.4\)
= \(\frac{2}{3}-\frac{1}{4}:\frac{3}{4}+\frac{5}{8}.4\)
= \(\frac{2}{3}-\frac{1}{3}+\frac{5}{2}\)
= \(\frac{1}{3}+\frac{5}{2}\)
= \(\frac{17}{6}\)
1)\(\frac{4^6.45}{2^4}=\frac{\left(2^2\right)^6.45}{2^4}=\frac{2^{12}.45}{2^4}=2^8.45=256.45=11520\)
2)\(\frac{8^5.16^3}{4^{13}}=\frac{8^5.\left(4^2\right)^3}{4^{13}}=\frac{8^5.4^6}{4^{13}}=\frac{8^5}{4^7}=\frac{\left(8^2\right)^2.8}{\left(4^3\right)^2.4}=\frac{64^2.8}{64^2.4}=\frac{8}{4}=2\)
3)Cái này bạn tự làm vì dễ rồi
4)\(\frac{45^{10}.5^{20}}{75^{15}}=\frac{\left(3^2.5\right)^{10}.5^{20}}{\left(5^2.3\right)^{15}}=\frac{3^{20}.5^{10}.5^{20}}{5^{30}.3^{15}}=\frac{3^{20}.5^{30}}{5^{30}.3^{15}}=3^5=243\)
Chúc bạn học tốt
Trả lời:
1,\(\frac{4^6\times45}{2^4}=\frac{\left(2^2\right)^6\times45}{2^4}\)
\(=\frac{2^{12}\times45}{2^4}\)
\(=2^8\times45\)
\(=256\times45\)
\(=11520\)
2,\(\frac{8^5\times16^3}{4^{13}}=\frac{\left(2^3\right)^5\times\left(2^4\right)^3}{\left(2^2\right)^{13}}\)
\(=\frac{2^{15}\times2^{12}}{2^{26}}\)
\(=\frac{2^{27}}{2^{26}}\)
\(=2\)
3,\(\frac{2^{10}\times13+2^{10}\times65}{2^8\times104}=\frac{2^{10}\times\left(13+65\right)}{2^8\times104}\)
\(=\frac{2^{10}\times78}{2^8\times104}\)
\(=\frac{2^2\times3}{4}\)
\(=\frac{4\times3}{4}\)
\(=3\)
4,\(\frac{45^{10}\times5^{20}}{75^{15}}=\frac{\left(5\times9\right)^{10}\times5^{20}}{\left(3\times25\right)^{10}}\)
\(=\frac{\left(5\times3^2\right)^{10}\times5^{20}}{\left(3\times5^2\right)^{15}}\)
\(=\frac{5^{10}\times3^{20}\times5^{20}}{3^{15}\times5^{30}}\)
\(=\frac{5^{30}\times3^{20}}{3^{15}\times5^{30}}\)
\(=3^5=243\)
Học tốt
e: \(=\dfrac{5^{30}\cdot3^{20}}{3^{15}\cdot5^{30}}=3^5=243\)
\(8\equiv1\left(mod7\right)\Rightarrow8^{13}\equiv1\left(mod7\right)\)
\(4^{20}=16.\left(4^3\right)^6=16.\left(64\right)^6=2.64^6+14.64^6\), mà \(64\equiv1\left(mod7\right)\Rightarrow2.64^3\equiv2\left(mod7\right)\)
\(\Rightarrow4^{20}\equiv2\left(mod7\right)\)
\(2^{41}=4.2^{39}=4.\left(2^3\right)^{13}=4.8^{13}\) , mà \(8\equiv1\left(mod7\right)\Rightarrow4.8^{13}\equiv4\left(mod7\right)\)
\(\Rightarrow8^{13}+4^{20}+2^{41}\equiv\left(1+2+4=7\right)\left(mod7\right)\)
Hay \(3^{13}+4^{20}+2^{41}⋮7\)