Tính biểu thức sau:  a) 3/5 +1/2 = …

Hướng dẫn: 

a) \(\frac{3}{5} + \frac{1}{2} = \frac{6}{{10}} + \frac{5}{{10}} = \frac{{11}}{{10}}\)
b) \(\frac{{14}}{{15}} - \frac{2}{3} = \frac{{14}}{{15}} - \frac{{10}}{{15}} = \frac{4}{{15}}\)
c) \(\frac{4}{6} \times \frac{5}{3} = \frac{{20}}{{18}} = \frac{{10}}{9}\)
d) \(4:\frac{2}{5} = 4 \times \frac{5}{2} = 10\)