Bài 1 :
a) \(\frac{5}{12}-\frac{7}{32}\div\frac{21}{16}=\frac{5}{12}-\frac{7}{32}\times\frac{16}{21}\)
\(=\frac{5}{12}-\frac{7\times16}{32\times21}\)
\(=\frac{5}{12}-\frac{1}{6}\)
\(=\frac{5}{12}-\frac{2}{12}\)
\(=\frac{5-2}{12}\)
\(=\frac{1}{4}\)
b) \(\frac{2}{3}+2\frac{1}{2}-\frac{3}{4}=\frac{2}{3}+\frac{5}{2}-\frac{3}{4}\)
\(=\frac{8}{12}+\frac{30}{12}-\frac{9}{12}\)
\(=\frac{8+30-9}{12}\)
\(=\frac{29}{12}\)
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