tính a) 5/6+1/3; b) 18/7-3/4;c)7/9*1/6;d) 1/6:3/9

* Hướng dẫn giải

$a)\frac{5}{6}+\frac{1}{3}=\frac{5}{6}+\frac{2}{6}=\frac{7}{6}$

$b)\frac{18}{7}-\frac{3}{4}=\frac{72}{28}-\frac{21}{28}=\frac{51}{28}$

$c)\frac{7}{9}\times \frac{1}{6}=\frac{7}{54}$

$d)\frac{1}{6}:\frac{3}{9}=\frac{1}{6}\times \frac{3}{1}=\frac{3}{6}=\frac{1}{2}$