G = \(\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{1536}\)
\(A=\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+...+\frac{1}{768}+\frac{1}{1536}\)
Tính nhanh :
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+...+\frac{1}{1536}+\frac{1}{3072}\)
\(\frac{1}{3}+\frac{1}{6}+\frac{1}{12}+\frac{1}{24}+...+\frac{1}{1536}+\frac{1}{3072}\)
\(=\frac{2}{3}-\frac{1}{3}+\frac{1}{3}-\frac{1}{6}+\frac{1}{6}-\frac{1}{12}+\frac{1}{12}-\frac{1}{24}+...+\frac{1}{1536}-\frac{1}{3072}\)
\(=\frac{2}{3}+\left(\frac{1}{3}-\frac{1}{3}\right)+\left(\frac{1}{6}-\frac{1}{6}\right)+\left(\frac{1}{12}-\frac{1}{12}\right)+...+\left(\frac{1}{1536}-\frac{1}{1536}\right)-\frac{1}{3072}\)
\(=\frac{2}{3}-\frac{1}{3072}\)
\(=\frac{2047}{3072}\)
a) \(\frac{14}{21}+1-|\frac{1}{3}-1|\)
b) \(\frac{1}{3}-|\frac{-1}{4}+\frac{5}{6}|-|\frac{-7}{12}|\)
c) \(|\frac{-5}{6}+\frac{1}{2}|-\frac{1}{3}+|\frac{-5}{12}|\)
d) \(\frac{-10}{6}-\frac{4}{-8}|\frac{-3}{4}+\frac{5}{-2}|\)
e) \(|\frac{-5}{2}|-|\frac{-4}{28}+1|-\frac{-3}{14}\)
g) \(\frac{5}{7}-|\frac{-4}{28}+\frac{1}{2}|-|\frac{-3}{14}|\)
Các bạn giúp mik bài này nhé. Càm ơn nhiều
a) \(\frac{14}{21}+1-\left|\frac{1}{3}-1\right|\)
\(=\frac{2}{3}+1-\frac{2}{3}\)
\(=1+\left(\frac{2}{3}-\frac{1}{3}\right)\)
\(=1\)
b) \(\frac{1}{3}-\left|\frac{-1}{4}+\frac{5}{6}\right|-\left|\frac{-7}{12}\right|\)
\(=\frac{1}{3}-\frac{7}{12}-\frac{7}{12}\)
\(=-\frac{5}{6}\)
\(\frac{1}{3}-|\frac{-1}{4}+\frac{5}{6}|-|\frac{-7}{12}|\)
\(=\frac{2}{3}+1-\frac{2}{3}\)
\(=1+(\frac{2}{3}-\frac{2}{3})\)
\(=1\)
Tính:
G=\(\frac{\frac{7}{12}+\frac{5}{6}-1}{5-\frac{3}{4}+\frac{1}{3}}\)
Giup mik nka
Tính giá trị của biểu thức hợp lí nếu có thể
g/ \(\frac{-2}{7}-\frac{1}{3}:\frac{-5}{21}\)
h/ \(\frac{3}{5}-\frac{3}{5}:\frac{2}{15}-1\frac{1}{3}\)
i/ \(\left(\frac{-1}{2}\right)^2-1\frac{1}{2}.\frac{8}{9}\)
k/ \(25+\left(\frac{17}{18}-\frac{5}{12}\right):3\frac{1}{6}\)
l/\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
Tính.
a) $\frac{1}{3} + \frac{1}{3} + \frac{1}{6}$
b) $\frac{1}{{12}} + \frac{3}{4} + \frac{2}{{12}}$
c) $\frac{{19}}{{15}} + 0 + \frac{{11}}{{15}}$
a) $\frac{1}{3} + \frac{1}{3} + \frac{1}{6} = \frac{2}{3} + \frac{1}{6} = \frac{4}{6} + \frac{1}{6} = \frac{5}{6}$
b) $\frac{1}{{12}} + \frac{3}{4} + \frac{2}{{12}} = \left( {\frac{1}{{12}} + \frac{2}{{12}}} \right) + \frac{3}{4} = \frac{1}{4} + \frac{3}{4} = \frac{4}{4} = 1$
c) $\frac{{19}}{{15}} + 0 + \frac{{11}}{{15}} = \frac{{19 + 11}}{{15}} = \frac{{30}}{{15}} = 2$
Bài 1:
\(E=\frac{\left(13\frac{1}{4}-2\frac{5}{27}-10\frac{5}{6}\right)\cdot230\frac{1}{25}+46\frac{3}{4}}{\left(1\frac{3}{7}+\frac{10}{3}\right)\div\left(12\frac{1}{3}-14\frac{2}{7}\right)}\)
Bài 2:
\(G=\frac{4,5\div\left[47,375-\left(26\frac{1}{3}-18\cdot0,75\right)\cdot2,4\div0,88\right]}{17,81\div1,37-23\frac{2}{3}\div1\frac{5}{6}}\)
kiểm tra hộ em
1/ thực hiện phép tính
a/\(\frac{1}{4}.\frac{2}{3}-\frac{3}{2}.\frac{1}{6}+\frac{1}{12}\)
=\(\frac{1}{6}-\frac{1}{4}+\frac{1}{12}\)
=\(\frac{2-3+1}{12}=\frac{-1+1}{12}=0\)
e,\(A=\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}=\left(1-\frac{1}{2}\right)+\left(1-\frac{1}{6}\right)+\left(1-\frac{1}{12}\right)+\left(1-\frac{1}{20}\right)+\left(1-\frac{1}{20}\right)+\left(1-\frac{1}{42}\right)\)
\(\Rightarrow A=1-\frac{1}{2}+1-\frac{1}{6}+1-\frac{1}{12}+1-\frac{1}{20}+1-\frac{1}{30}+1-\frac{1}{42}=4-\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\right)\)
\(\Rightarrow A=4-\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}\right)=4-\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\right)\)
\(\Rightarrow A=4-\left(\frac{1}{1}-\frac{1}{7}\right)=4-\frac{6}{7}=3\frac{1}{7}\)
BN mún hỏi j vậy, đây k phải câu hỏi, mà có thì phải là toán lớp 6