Tính: 2/5 + 1/2

a) \(\frac{2}{5} + \frac{1}{2} = \frac{9}{{10}}\)

Giải thích:

\(\frac{2}{5} + \frac{1}{2}\) = \(\frac{4}{{10}} + \frac{5}{{10}}\) = \(\frac{9}{{10}}\)

c) \(\frac{3}{2} - \frac{1}{3} = \,\frac{7}{6}\)

Giải thích:

\(\frac{3}{2} - \frac{1}{3}\) = \(\frac{9}{6}\,\, - \,\,\frac{2}{6}\)= \(\,\frac{7}{6}\)

b) \(\frac{{36}}{7} \times \frac{3}{4} = \,\,\frac{{27}}{7}\)

Giải thích:

\(\frac{{36}}{7} \times \frac{3}{4}\) = \(\frac{{4 \times 9\,\, \times 3}}{{7 \times \,\,4}}\,\,\)= \(\frac{{27}}{7}\,\,\)

d) \(\frac{{16}}{5}:\frac{3}{5} = \,\,\frac{{16}}{3}\)

Giải thích:

\(\frac{{16}}{5}:\frac{3}{5}\)  = 165​​  ×​  53 =  \(\frac{{16}}{3}\)