Tính biểu thức:   a) 25/6 +1/3 =

Hướng dẫn: 

a) \(\frac{{25}}{6} + \frac{1}{3} = \frac{{75}}{{18}} + \frac{6}{{18}} = \frac{{81}}{{18}} = \frac{9}{2}\)

b) \(\frac{5}{8} - \frac{1}{3} = \frac{{15}}{{24}} - \frac{8}{{24}} = \frac{7}{{24}}\)

c) \(\frac{9}{{100}} \times \frac{4}{4} = \frac{9}{{100}} \times 1 = \frac{9}{{100}}\)

d) \(\frac{6}{{12}}:\frac{1}{4} = \frac{6}{{12}} \times \frac{4}{1} = \frac{{24}}{{12}} = 2\)