a)

\(\begin{array}{l}M = \frac{1}{2} + \frac{2}{3} + \left( { - \frac{1}{2}} \right) + \frac{1}{3}\\ = \frac{3}{6} + \frac{4}{6} + \left( {\frac{{ - 3}}{6}} \right) + \frac{2}{6}\\ = \frac{{3 + 4 + \left( { - 3} \right) + 2}}{6}\\ = \frac{6}{6} = 1\end{array}\)

b)

\(\begin{array}{l}M = \frac{1}{2} + \frac{2}{3} + \left( { - \frac{1}{2}} \right) + \frac{1}{3}\\ = \left[ {\frac{1}{2} + \left( {\frac{{ - 1}}{2}} \right)} \right] + \left[ {\frac{2}{3} + \frac{1}{3}} \right]\\ = 0 + 1 = 1\end{array}\)

\(\frac{1-\frac{1}{3}+\frac{1}{1+\frac{1}{3}}}{1-\frac{1}{3}-\frac{1}{1+\frac{1}{3}}}=\frac{\frac{2}{3}+\frac{1}{\frac{4}{3}}}{\frac{2}{3}-\frac{1}{\frac{4}{3}}}=\frac{\frac{2}{3}+\frac{3}{4}}{\frac{2}{3}-\frac{3}{4}}=\frac{\left(\frac{2}{3}+\frac{3}{4}\right).12}{\left(\frac{2}{3}-\frac{3}{4}\right).12}=\frac{8+9}{8-9}=\frac{17}{-1}=-17\)

Sai đâu bỏ qua nhé, hơi to mới lại mk tính máy tính ra : \(\frac{77}{30}\)nên ko chắc nhé 

\(2+\frac{1}{1+\frac{1}{1+\frac{1}{3+\frac{1}{4}}}}=2+\frac{1}{1+\frac{1}{1+\frac{1}{\frac{13}{4}}}}\)

\(=2+\frac{1}{1+\frac{1}{1+\frac{4}{13}}}=2+\frac{1}{1+\frac{1}{\frac{17}{3}}}\)

\(=2+\frac{1}{1+\frac{3}{17}}=2+\frac{1}{\frac{20}{17}}=2+\frac{17}{20}=\frac{57}{20}\)

Biết sai đâu rồi nhé, sai dòng 2 nhé 

\(=2+\frac{1}{1+\frac{1}{\frac{17}{13}}}=2+\frac{1}{1+\frac{13}{17}}\)

\(=2+\frac{1}{\frac{30}{17}}=2+\frac{17}{30}=\frac{77}{30}\)

Áp dụng quy tắc \(\frac{a}{b}=\frac{1}{\frac{b}{a}}\), ta có:

\(2+\frac{1}{1+\frac{1}{1+\frac{1}{3+\frac{1}{4}}}}=2+\frac{1}{1+\frac{1}{1+\frac{1}{\frac{13}{4}}}}=2+\frac{1}{1+\frac{1}{1+\frac{4}{13}}}=2+\frac{1}{1+\frac{1}{\frac{17}{13}}}=2+\frac{1}{1+\frac{13}{17}}\)

\(=2+\frac{1}{\frac{30}{17}}=2+\frac{17}{30}=\frac{77}{30}\)

\(\begin{array}{l} - \left( { - \frac{3}{4}} \right) - \left( {\frac{2}{3} + \frac{1}{4}} \right)\\ = \frac{3}{4} - \frac{2}{3} - \frac{1}{4}\\ = \left( {\frac{3}{4} - \frac{1}{4}} \right) - \frac{2}{3}\\ = \frac{2}{4} - \frac{2}{3}\\= \frac{1}{2} - \frac{2}{3}\\ = \frac{3}{6} - \frac{4}{6}\\ = \frac{{ - 1}}{6}\end{array}\)

\(5+\frac{1}{1+\frac{1}{1+\frac{2}{1+\frac{3}{4}}}}\)\(=5+\frac{15}{7}=\frac{50}{7}\)

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Đỗ Ngọc Hải cần gấp

 Đúng 0             

bằng \(-\frac{2}{3}\)

nhé

bằng phân số \(\frac{-2}{3}\)nhé nhớ tích nhé

\(\frac{-2}{3}\)

\(\frac{3}{29}-\frac{1}{5}.\frac{29}{3}=\frac{3}{29}-\frac{29}{15}=\frac{-362}{145}\)

3/29 - 1/5 . 29/3

= 3/29 . 29/3 - 1/5

= 1 - 1/5

= 5/5 - 1/5

= 4/5

3/29 - 1/5 . 29/3

= 3/29 . 29/3 - 1/5

= 1 - 1/5

= 4/5

#hoc_tot#