Ta có: \(1-\frac12+\frac13-\frac14+\cdots+\frac{1}{567}-\frac{1}{568}\)

\(=1+\frac12+\frac13+\frac14+\cdots+\frac{1}{568}-2\left(\frac12+\frac14+\cdots+\frac{1}{568}\right)\)

=\(1+\frac12+\frac13+\frac14+\cdots+\frac{1}{568}-1-\frac12-\cdots-\frac{1}{284}\)

\(=\frac{1}{285}+\frac{1}{286}+\cdots+\frac{1}{568}\)

Ta có: \(C=\frac{\frac{1}{285}+\frac{1}{286}+\cdots+\frac{1}{568}}{1-\frac12+\frac13-\frac14+\cdots+\frac{1}{567}-\frac{1}{568}}\)

\(=\frac{\frac{1}{285}+\frac{1}{286}+\cdots+\frac{1}{568}}{\frac{1}{285}+\frac{1}{286}+\cdots+\frac{1}{568}}\)

=1

A=1234x1001001x5678-5678x1001001x1234

A=0

A=1234x5678-5678x1234

A=0

Bài 1:

a) Ta có:

\(-3\dfrac{1}{5}=-2,8\)

\(\dfrac{37}{10}=3,7\)

Vì \(-3,25< -2,8< 3,7\)

Nên \(-3,25< -3\dfrac{1}{5}< \dfrac{37}{10}\)

b) Ta có:

\(\dfrac{-567}{568}>-1\)

\(\dfrac{-568}{567}< -1\)

\(\Leftrightarrow\dfrac{-567}{568}>-1>\dfrac{-568}{567}\)

\(\Leftrightarrow\dfrac{-567}{568}>\dfrac{-568}{567}\)

c) \(-0,625=-\dfrac{5}{8}\)

Vì \(8>7\)

\(\Leftrightarrow\dfrac{1}{8}< \dfrac{1}{7}\)

\(\Leftrightarrow\dfrac{-5}{8}>\dfrac{-5}{7}\)

\(\Leftrightarrow-0,625>\dfrac{-5}{7}\)

Vậy ...

Giải:

a) \(3,6-\dfrac{-5}{6}.\left(-2,4\right).\dfrac{3}{5}\)

\(=\dfrac{18}{5}-\dfrac{-5}{6}.\left(-\dfrac{12}{5}\right).\dfrac{3}{5}\)

\(=\dfrac{18}{5}-\dfrac{6}{5}\)

\(=\dfrac{12}{5}\)

Vậy ...

b) \(\dfrac{1}{4}-0,5-6\dfrac{1}{2}+\dfrac{5}{8}\)

\(=\dfrac{1}{4}-\dfrac{1}{2}-6\dfrac{1}{2}+\dfrac{5}{8}\)

\(=-\dfrac{49}{8}\)

Vậy ...

c) \(1,1-\left(-1,2\right)-\left|-1,3\right|-2\dfrac{3}{4}\)

\(=1,1+1,2-1,3-2,75\)

\(=-\dfrac{7}{4}=-1,75\)

Vậy ...

mik ko hieu lam

Tìm x :

x - 0,27 = \(\frac{73}{100}\)

x           = \(\frac{73}{100}+0,27\)

x           = 1

Cậu P khó quá mik chưa nghĩ ra cách tính nhanh nhất !

Cậu tự giải nhé !

Hok tốt

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