Tính
\(\begin{array}{l}
a)6\frac{3}{8} + 5\frac{1}{2}\\
b)5\frac{3}{7} - 2\frac{3}{7}\\
c) - 5\frac{1}{7} + 3\frac{2}{5}\\
d) - 2\frac{1}{3} - 1\frac{2}{7}
\end{array}\)
\(\begin{array}{l}
a)6\frac{3}{8} + 5\frac{1}{2} = 6 + 5 + \left( {\frac{3}{8} + \frac{1}{2}} \right)\\
= 11 + \frac{7}{8} = 11\frac{7}{8}\\
b)5\frac{3}{7} - 2\frac{3}{7} = 5 - 2 + \left( {\frac{3}{7} - \frac{3}{7}} \right)\\
= 3 + 0 = 3\\
c) - 5\frac{1}{7} + 3\frac{2}{5} = - 5 + 3 + \left( {\frac{1}{7} + \frac{2}{5}} \right)\\
= - 2 + \left( {\frac{{ - 5}}{{35}} + \frac{{14}}{{35}}} \right)\\
= - 2 + \frac{9}{{35}} = \frac{{ - 61}}{{35}}\\
d) - 2\frac{1}{3} - 1\frac{2}{7} = - \frac{7}{3} - \frac{9}{7}\\
= \frac{{ - 49}}{{21}} - \frac{{27}}{{21}} = \frac{{ - 76}}{{21}}
\end{array}\)
-- Mod Toán 6
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