Thực hiện các phép tính sau: (a) 9/5 − 3/4 + 7/10 . (b) − 5/11 ⋅ 11/45 + 5/6 : 15/2 .

a) \(\frac{9}{5} - \frac{3}{4} + \frac{7}{{10}}\)

\( = \frac{{36}}{{20}} - \frac{{15}}{{20}} + \frac{{14}}{{20}}\)

\( = \frac{{35}}{{20}} = \frac{7}{4}.\)

b) \(\frac{{ - 5}}{{11}} \cdot \frac{{11}}{{45}} + \frac{5}{6}:\frac{{15}}{2}\)

\( = \frac{{ - 1}}{9} + \frac{5}{6} \cdot \frac{2}{{15}}\)

\( = \frac{{ - 1}}{9} + \frac{1}{9} = 0.\)