Question

\frac{3}{5} + \frac{2}{1} . \frac{3}{8} - \frac{3}{20} . \frac{7}{2}

Answer 1

${3\over5}+{2\over1}\times{3\over8}+{3\over20}\times{7\over2}=$

1° calcular as multiplicações ,

${3\over5}+{6\over8}+{21\over40}=\\ \\ mmc(5,8,40)=40\\ \\ {3\over5}+{6\over8}+{21\over40}={75\over40}={75:5\over40:5}={15\over8}$