\(=\frac{4}{1+\frac{1}{\frac{4}{3}}}=\frac{4}{1+\frac{3}{4}}=\frac{4}{\frac{7}{4}}=4:\frac{7}{4}=4\cdot\frac{4}{7}=\frac{16}{7}\)
\(=\frac{4}{1+\frac{1}{\frac{4}{3}}}=\frac{4}{1+\frac{3}{4}}=\frac{4}{\frac{7}{4}}=4:\frac{7}{4}=4\cdot\frac{4}{7}=\frac{16}{7}\)
a,A=\(\frac{1}{2}-\frac{1}{2^2}+\frac{1}{2^3}-\frac{1}{2^4}+...+\frac{1}{2^{99}}-\frac{1}{2^{100}}\)
b,B=\(\frac{1}{1\times2\times3}+\frac{1}{2\times3\times4}+\frac{1}{3\times4\times5}+...+\frac{1}{998\times999\times100}\)
c,C=\(\frac{1+\left(1+2\right)+\left(1+2+3\right)+...+\left(1+2+3+...+98\right)}{1\times98+2\times97+3\times96+...+98\times1}\)
Tìm x biết:
a) \(^{2^x+2^{x+1}+2^{x+2}+2^{x+3}=480}\)
b) \(\left(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2012}+\frac{1}{2013}\right).x=\frac{2012}{1}+\frac{2011}{2}+\frac{2010}{3}+...+\frac{2}{2011}+\frac{1}{2012}\)
bài 1 : sắp xếp theo thứ tự tăng dần : \(\frac{1}{2};\frac{1}{3};\frac{1}{38};\frac{-1}{12};\frac{-7}{9};\frac{-6}{9};0;\frac{9}{11};\frac{3}{2}\)
Tính nhanh giá trị biểu thức sau:
a) \(-\frac{9}{10}\cdot\frac{5}{14}+\frac{1}{10}\cdot\left(-\frac{9}{2}\right)+\frac{1}{7}\cdot\left(-\frac{9}{10}\right)\)
b)\(\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{6}+\frac{1}{11}\right)\cdot132\)
c)\(-\frac{2}{3}\cdot\left(\frac{8}{9}\cdot\frac{8}{13}-\frac{8}{27}\cdot\frac{3}{13}+\frac{4}{3}\cdot\frac{22}{39}\right)\)
Cho M=\(\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+\frac{1}{1+2+3+...+39}\)
CMR:M<\(\frac{2}{3}\)
sắp xếp theo thứ tự tăng dần : \(\frac{1}{3};\frac{1}{5};\frac{-2}{15};\frac{1}{6};\frac{-2}{-5};\frac{-1}{10};\frac{4}{15}\)
bài 1 : thực hiện phép tính
1) \(\frac{2}{3}+\frac{3}{4}+\frac{-1}{6}\) 2) \(\frac{1}{2}-\frac{2}{5}+\frac{-7}{10}\)
Giúp mk vs mn ơi!!!!!!
Bài tập: Chứng minh \(1-\frac{1}{2}-\frac{1}{2^2}-\frac{1}{2^3}-...-\frac{1}{2^{2014}}>\frac{1}{2^{2015}}\)
tính
B=\(\frac{\left(\frac{1}{2}\right)^{10}.5-\left(\frac{1}{4}\right)^5.3}{\frac{1}{1024}.\frac{1}{3}-\left(\frac{1}{2}\right)^{11}}\)