\(2-\frac{1}{15}=\)
Những câu hỏi liên quan
\(\frac{1+15^4+15^8+...+15^{96}+15^{100}}{1+\frac{15}{2}+\frac{15}{4}+...+\frac{15}{100}+\frac{15}{102}}\)
Giúp mình với nhé:
Tính:
a)\(\left(\frac{1}{2^2-1}\right).\left(\frac{1}{3^2-1}\right).\left(\frac{1}{4^2-1}\right)...\left(\frac{1}{98^2-1}\right).\left(\frac{1}{99^2-1}\right)\)
b)\(4\frac{1}{2}-\frac{15}{10.9}-\frac{15}{9\cdot8}-\frac{15}{3.2}-\frac{15}{2.1}\)
\(\frac{2}{7}.\frac{12}{15}+\frac{12}{15}.\frac{3}{7}+\frac{12}{15}.\frac{1}{7}+\frac{12}{15}.\frac{1}{7}\)
giải: 12/15(2/7+3/7+1/7+1/7)=12/15.7/7=12/15=4/5
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\(=\frac{12}{15}.\left(\frac{2}{7}+\frac{3}{7}+\frac{1}{7}+\frac{1}{7}\right)\)
\(=\frac{12}{15}.1\)
\(=\frac{12}{15}=\frac{4}{5}\)
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Tính:
\(\left(-1\frac{1}{2}\right).\left(-1\frac{1}{3}\right).....\left(-1\frac{1}{2003}\right).\left(-1\frac{1}{2004}\right)\)
A=\(\frac{15}{2.5}+\frac{15}{5.8}+\frac{15}{8.11}....+\frac{15}{32.35}\)
\(3x-\frac{15}{5.8}-\frac{15}{8.11}-\frac{15}{11.14}-...-\frac{15}{47.50}=2\frac{1}{10}\)
\(3x-\frac{15}{5\cdot8}-\frac{15}{8\cdot11}-\frac{15}{11\cdot14}-...-\frac{15}{47\cdot50}=2\frac{1}{10}\)
<=> \(3x-5\left(\frac{3}{5\cdot8}+\frac{3}{8\cdot11}+\frac{3}{11\cdot14}+...+\frac{3}{47\cdot50}\right)=\frac{21}{10}\)
<=> \(3x-5\left(\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+...+\frac{1}{47}-\frac{1}{50}\right)=\frac{21}{10}\)
<=> \(3x-5\left(\frac{1}{5}-\frac{1}{50}\right)=\frac{21}{10}\)
<=> \(3x-5\cdot\frac{9}{50}=\frac{21}{10}\)
<=> \(3x-\frac{9}{10}=\frac{21}{10}\)
<=> \(3x=3\)
<=> \(x=1\)
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) $\frac{{19}}{{15}} + 0 + \frac{{11}}{{15}} = \frac{{19 + 11}}{{15}} = \frac{{30}}{{15}} = 2$
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sắp xếp theo thứ tự tăng dần : \(\frac{1}{3};\frac{1}{5};\frac{-2}{15};\frac{1}{6};\frac{-2}{-5};\frac{-1}{10};\frac{4}{15}\)
sắp xếp theo thứ tự tăng dần là:
\(\Rightarrow-\frac{2}{15};-\frac{1}{10};\frac{1}{6};\frac{1}{5};\frac{4}{15};\frac{1}{3}\)
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mình nghĩ là ta nên quy đồng trước
a)\(\left(15-6\frac{13}{18}\right):11\frac{1}{27}-2\frac{1}{8}:1\frac{11}{40}\)
b) \(\left(-3,2\right).\frac{-15}{64}+\left(0,8-2\frac{4}{15}\right):3\frac{2}{3}\)
A/ \(\left(15-6\frac{13}{18}\right):11\frac{1}{27}-2\frac{1}{8}:1\frac{11}{40}\)
\(=\left(15-\frac{121}{18}\right):\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\)
\(=\left(\frac{270}{18}-\frac{121}{18}\right):\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\)
\(=\frac{149}{18}:\frac{298}{27}-\frac{17}{8}:\frac{51}{40}\)
\(=\frac{3}{4}-\frac{5}{3}\)
\(=\frac{9}{12}-\frac{20}{12}\)\(=-\frac{11}{12}\)
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B/ \(\left(-3,2\right)\cdot-\frac{15}{64}+\left(0,8-2\frac{4}{15}\right):3\frac{2}{3}\)
\(=\left(-3,2\right)\cdot-\frac{15}{64}+\left(0,8-\frac{34}{15}\right):\frac{11}{3}\)
\(=-\frac{3,2}{1}\cdot-\frac{15}{64}+\left(0,8-\frac{34}{15}\right):\frac{11}{3}\)
\(=\frac{48}{64}+\left(0,8-\frac{34}{15}\right):\frac{11}{3}\)
\(=\frac{3}{4}+\left(\frac{12}{15}-\frac{34}{15}\right):\frac{11}{3}\)
\(=\frac{3}{4}+\left(-\frac{22}{15}\right):\frac{11}{3}\)
\(=\frac{3}{4}+\left(-\frac{2}{5}\right)\)
\(=\frac{15}{20}+\left(-\frac{8}{20}\right)\)
\(=\frac{7}{20}\)
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Thực hiện phép tính
a,(frac{-5}{28}+1,75+frac{8}{35}).(-3frac{9}{20}) b,(6-2frac{4}{5}).3frac{1}{8}-1frac{3}{5}:frac{1}{4}
c,(frac{7-5}{24}+0,75+frac{7}{12}):(-2frac{1}{8}) d,8frac{2}{7}-(3frac{4}{7}+4frac{2}{7})
e,left(-3,2right).frac{-15}{64}+(0,8-2frac{4}{15}):3frac{2}{3} f,1frac{13}{15}.left(0,5right)^2.3+(frac{8}{15}-1frac{19}{60}):1frac{23}{24}
g,1,4.frac{15}{49}-(frac{4}{5}+frac{2}{3}):2f...
Đọc tiếp
Thực hiện phép tính
\(a,(\frac{-5}{28}+1,75+\frac{8}{35}).(-3\frac{9}{20})\) \(b,(6-2\frac{4}{5}).3\frac{1}{8}-1\frac{3}{5}:\frac{1}{4}\)
\(c,(\frac{7-5}{24}+0,75+\frac{7}{12}):(-2\frac{1}{8})\) \(d,8\frac{2}{7}-(3\frac{4}{7}+4\frac{2}{7})\)
\(e,\left(-3,2\right).\frac{-15}{64}+(0,8-2\frac{4}{15}):3\frac{2}{3}\) \(f,1\frac{13}{15}.\left(0,5\right)^2.3+(\frac{8}{15}-1\frac{19}{60}):1\frac{23}{24}\)
\(g,1,4.\frac{15}{49}-(\frac{4}{5}+\frac{2}{3}):2\frac{1}{5}\)
a: \(=\left(-\dfrac{25}{140}+\dfrac{245}{140}+\dfrac{32}{140}\right)\cdot\dfrac{-69}{20}\)
\(=\dfrac{252}{140}\cdot\dfrac{-69}{20}\)
\(=\dfrac{9}{5}\cdot\dfrac{-69}{20}=\dfrac{-621}{100}\)
b: \(=\left(6-2-\dfrac{4}{5}\right)\cdot\dfrac{25}{8}-\dfrac{8}{5}\cdot4\)
\(=\dfrac{16}{5}\cdot\dfrac{25}{8}-\dfrac{32}{5}=\dfrac{18}{5}\)
c: \(=\left(\dfrac{2}{24}+\dfrac{18}{24}+\dfrac{14}{24}\right):\dfrac{-17}{8}\)
\(=\dfrac{34}{24}\cdot\dfrac{-8}{17}=\dfrac{-1}{3}\cdot2=-\dfrac{2}{3}\)
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Tìm số nằm giữa \(\frac{-1}{3}\)và\(\frac{-1}{5}\).Giải thích rõ vì sao.
\(-\frac{1}{4};-\frac{8}{15};\frac{2}{-15};\frac{-4}{15};\frac{1}{-2}.\)