Đề bài

Bài 1 (6.38). Tính:

a) $\frac{{ - 1}}{2} + \frac{5}{6} + \frac{1}{3};$                   

b) $\frac{{ - 3}}{8} + \frac{7}{4} - \frac{1}{{12}};$

c) $\frac{3}{5}:\left( {\frac{1}{4}.\frac{7}{5}} \right);$                   

d) $\frac{{10}}{{11}} + \frac{4}{{11}}:4 - \frac{1}{8}.$