Tính tổng:

a) \[\frac{1}{8} + \frac{3}{8} + \frac{9}{8}\];

b) \[\frac{1}{{20}} + \frac{3}{4} + \frac{6}{5}\];

c) \[\frac{3}{4} + \frac{1}{{25}} + \frac{3}{{100}}\];

d) \(\frac{2}{7} + \frac{3}{{25}} + \frac{7}{5}\).

a) \[\frac{1}{8} + \frac{3}{8} + \frac{9}{8} = \frac{{1 + 3 + 9}}{8} = \frac{{13}}{8}\].

b) \[\frac{1}{{20}} + \frac{3}{4} + \frac{6}{5} = \frac{1}{{20}} + \frac{{15}}{{20}} + \frac{{24}}{{20}}\]

\[ = \frac{{1 + 15 + 24}}{{20}} = \frac{{40}}{{20}} = 2\].

c) \[\frac{3}{4} + \frac{1}{{25}} + \frac{3}{{100}} = \frac{{75}}{{100}} + \frac{4}{{100}} + \frac{3}{{100}}\]

\[ = \frac{{75 + 4 + 3}}{{100}} = \frac{{82}}{{100}} = \frac{{41}}{{50}}\].

d) \(\frac{2}{7} + \frac{3}{{25}} + \frac{7}{5} = \frac{{50}}{{175}} + \frac{{21}}{{175}} + \frac{{245}}{{175}}\)

\( = \frac{{50 + 21 + 245}}{{175}} = \frac{{316}}{{175}}\).