Question

Tính bằng cách thuận tiện nhất :

a) \(\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)

b) \(\frac{9}{13}+\frac{4}{13}+\frac{2}{3}\)

Answer 1

a \(\frac{7}{6}\)

b \(\frac{5}{3}\)

Answer 2

\(a,\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)

\(=\left(\frac{2}{5}+\frac{3}{5}\right)+\frac{1}{6}\)

\(=1+\frac{1}{6}\)

\(=\frac{7}{6}\)

Hok tốt!~

Answer 3

\(\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)

\(=\frac{2}{5}+\frac{3}{5}+\frac{1}{6}\)

\(=\frac{5}{5}+\frac{1}{6}\)

\(=1+\frac{1}{6}\)

\(=1\frac{1}{6}=\frac{7}{6}\)

Answer 4

\(\frac{9}{13}+\frac{4}{13}+\frac{2}{3}\)

\(=\left(\frac{9}{13}+\frac{4}{13}\right)+\frac{2}{3}\)

\(=\frac{13}{13}+\frac{2}{3}\)

\(=1+\frac{2}{3}\)

\(=1\frac{2}{3}\)

\(=\frac{5}{3}\)