Tính: \(\left(\frac{3}{7}\right)^{20}\div\left(\frac{9}{49}\right)^5\)
Tính:
a) \(25^{3\div}5^2\)
b) \(\left(\frac{3}{7}\right)^{21}\div\left(\frac{9}{49}\right)^6\)
c) \(3-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right)^2\div2\)
a) \(25^3:5^2=5^6:5^2=5^4=625\)
b) \(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{12}=\left(\frac{3}{7}\right)^9\)
c) \(3-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right)^2:2=3-1+\frac{1}{8}=\frac{17}{8}\)
a) \(25^3:5^2=5^6:5^2=5^{6-2}=5^4\)
Tính \(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^5\)
Bài làm
\(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^5\)
= \(\left(\frac{3}{7}\right)^{20}:\left(\frac{3}{7}^2\right)^5\)
= \(\left(\frac{3}{7}\right)^{20}:\left(\frac{3}{7}\right)^{10}\)
= \(\left(\frac{3}{7}\right)^{20-10}\)
= \(\left(\frac{3}{7}\right)^{10}\)
# Chúc bạn học tốt #
\(\left(\frac{3}{7}\right)^{20}=\left(\frac{9}{49}\right)^{10}\)
Rồi tự làm
\(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^5\)
\(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^5\)
\(=\left[\left(\frac{3}{7}\right)^2\right]^{10}:\left[\left(\frac{3}{7}\right)^2\right]^5\)
\(=\left[\left(\frac{3}{7}\right)^2\right]^5\)
\(=\left(\frac{3}{7}\right)^{10}\)
Tính
\(b.\left(\frac{3}{7}\right)^{21}\div\left(\frac{9}{49}\right)^6\)
\(c.3-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right)^2\div2\)
b, \(\left(\frac{3}{7}\right)^{21}:\left(\frac{9}{49}\right)^6=\left(\frac{3}{7}\right)^{21}:\left[\left(\frac{3}{7}\right)^2\right]^6=\left(\frac{3}{7}\right)^{21}:\left(\frac{3}{7}\right)^{12}=\left(\frac{3}{7}\right)^{21-12}=\left(\frac{3}{7}\right)^9\)
Tính tổng:
\(B=\left(\frac{-3}{5}+\frac{4}{9}\right)\div\frac{7}{11}+\left(\frac{-2}{5}+\frac{5}{9}\right)\div\frac{7}{11}\)
\(B=\left(\frac{-3}{5}+\frac{4}{9}\right)\div\frac{7}{11}+\left(-\frac{2}{5}+\frac{5}{9}\right)\div\frac{7}{11}\)
\(B=\left(\frac{-3}{5}+\frac{4}{9}\right).\frac{7}{11}+\left(\frac{-2}{5}+\frac{5}{9}\right).\frac{7}{11}\)
\(B=\frac{7}{11}.\left(\frac{-3}{5}+\frac{-2}{5}+\frac{4}{9}+\frac{5}{9}\right)\)
\(B=\frac{7}{11}\left(\frac{-5}{5}+\frac{9}{9}\right)\)
\(B=\frac{7}{11}.\left(-1+1\right)=\frac{7}{11}.0=0\)
Tính nhanh:
A=\(\left(\frac{2}{5}+\frac{2}{9}+\frac{2}{11}\div\frac{7}{5}+\frac{7}{9}+\frac{7}{11}\right)\div\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{5}\div\frac{7}{6}-\frac{7}{8}+\frac{7}{10}\right)\)
a= (\(\frac{2}{5}\)+\(\frac{2}{9}\)+\(\frac{2}{11}\)\(\times\)\(\frac{5}{7}\)\(+\frac{7}{9}\)\(+\frac{7}{11}\)\()\)
Thức hiienj phép tính . (tính nhanh nếu có thể )
\(\frac{\left(\frac{2}{5}\right)^7\cdot5^7+\left(\frac{9}{4}\right)^3 \div\left(\frac{3}{16}\right)^3}{2^7\cdot5^7+512}\)
\(\frac{\left(\frac{2}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^7+512}\)
\(=\frac{\left(\frac{2}{5}.5\right)^7+\left(\frac{9}{4}:\frac{3}{16}\right)^3}{\left(2.5\right)^7+8^3}\)
\(=\frac{2^7+12^3}{10^7+8^3}\)
Từ đây tính nốt nha!
Thực hiện phép tính (hợp lí nếu có thể):
\(1,\frac{-1}{3}-\frac{-3}{5}-\frac{1}{6}+\frac{1}{43}-\frac{-3}{7}+\frac{-1}{2}-\frac{1}{35}\\ \\ 2,\left(-\frac{1}{3}+\frac{7}{13}\right)-\left(\frac{-16}{24}+\frac{6}{26}+\frac{9}{13}\right)\)\(3,\frac{-7}{3}-\left[\frac{2}{5}-\left(\frac{1}{3}+\frac{-5}{25}\right)\right]\\ 4,\left(2\frac{1}{4}-3\frac{1}{5}\right)-\left[\frac{-3}{4}+\left(\frac{4}{5}-2019\right)\right]\)
Thực hiện phép tính: E =\(\frac{0,8:\left(\frac{4}{5}.1,25\right)}{0,64-\frac{1}{25}}+\frac{\left(1,08-\frac{2}{25}\right):\frac{4}{7}}{\left(6\frac{5}{9}-3\frac{1}{4}\right).2\frac{2}{17}}\)+ (1,2 . 0,5 ) : \(\frac{4}{5}\)
Bấm máy tính:
E = \(\frac{4}{3}+\frac{1}{4}+\frac{3}{5}:\frac{4}{5}\)
E = \(\frac{4}{3}+\frac{1}{4}+\frac{3}{4}\)
E = \(\frac{7}{3}\)
Vậy E = \(\frac{7}{3}\)