Giải câu 4 trang 121 toán VNEN 4 tập 2.
$\frac{3}{5} + \frac{1}{3} = \frac{3}{5}+\frac{1}{3}=\frac{9}{15}+\frac{5}{15}=\frac{14}{15}$
$\frac{7}{16} - \frac{3}{8}= \frac{7}{16}-\frac{6}{8}=\frac{1}{16}$
$\frac{5}{6} : \frac{2}{3}= \frac{5}{6} : \frac{2}{3}= \frac{5}{6}\times \frac{3}{2}=\frac{15}{12}=\frac{5}{4}$
$\frac{15}{11}-\frac{3}{11}\times 4=\frac{15}{11}-\frac{12}{11}=\frac{3}{11}$