Nội dung bài giảng
Bài 2. Tính:
\(a)\,\frac{5}{8} - \frac{2}{5};\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,b)\,1\frac{1}{{10}} - \frac{3}{4};\,\,\,\,\,\,\,\,\,\,\,\,\,c)\,\frac{2}{3} + \frac{1}{2}\, - \frac{5}{6}\)
Bài làm
\(\begin{array}{l}
a)\,\frac{5}{8} - \frac{2}{5} = \frac{{25}}{{40}} - \frac{{16}}{{40}} = \frac{9}{{40}}\\
b)\,1\frac{1}{{10}} - \frac{3}{4} = \frac{{11}}{{10}} - \frac{3}{4} = \frac{{22}}{{20}} - \frac{{15}}{{20}} = \frac{7}{{20}}\\
c)\,\frac{2}{3} + \frac{1}{2}\, - \frac{5}{6} = \frac{4}{6} + \frac{3}{6} - \frac{5}{6} = \frac{{4 + 3 - 5}}{6} = \frac{2}{6} = \frac{1}{3}
\end{array}\)