Tính: 1/3+5/2-1/4

Lời giải

a) \(\frac{1}{3} + \frac{5}{2} - \frac{1}{4} = \frac{4}{{12}} + \frac{{30}}{{12}} - \frac{3}{{12}}\)

                       \( = \frac{{4 + 30 - 3}}{{12}} = \frac{{31}}{{12}}\)

b)\(\frac{1}{2} \times \frac{5}{7}:\frac{1}{3} = \frac{1}{2} \times \frac{5}{7} \times \frac{3}{1}\)

                 \( = \frac{{1 \times 5 \times 3}}{{2 \times 7 \times 1}} = \frac{{15}}{{14}}\)