\(a,\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)
\(=\left(\frac{2}{5}+\frac{3}{5}\right)+\frac{1}{6}\)
\(=1+\frac{1}{6}\)
\(=\frac{7}{6}\)
Hok tốt!~
\(\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)
\(=\frac{2}{5}+\frac{3}{5}+\frac{1}{6}\)
\(=\frac{5}{5}+\frac{1}{6}\)
\(=1+\frac{1}{6}\)
\(=1\frac{1}{6}=\frac{7}{6}\)
\(\frac{9}{13}+\frac{4}{13}+\frac{2}{3}\)
\(=\left(\frac{9}{13}+\frac{4}{13}\right)+\frac{2}{3}\)
\(=\frac{13}{13}+\frac{2}{3}\)
\(=1+\frac{2}{3}\)
\(=1\frac{2}{3}\)
\(=\frac{5}{3}\)