Question

tính nhanh

\(\frac{4}{6}\)+\(\frac{7}{13}\)+\(\frac{17}{9}\)+\(\frac{19}{13}\)+\(\frac{1}{9}\)+\(\frac{14}{6}\)

\(\frac{1}{9}\)+\(\frac{7}{12}\)+\(\frac{2}{9}\)+\(\frac{1}{12}\)+\(\frac{4}{12}\)+\(\frac{6}{9}\)

Answer 1

a/ \(\left[\frac{4}{6}+\frac{14}{6}\right]+\left[\frac{7}{13}+\frac{19}{13}\right]+\left[\frac{17}{9}+\frac{1}{9}\right]=\frac{18}{6}+\frac{26}{13}+\frac{18}{9}=3+2+2=7\)

Answer 2

4/6 + 7/13 + 17/9 + 19/13 + 1/9 + 14/6

= (4/6 + 14/6) + (7/13 + 19/13) + (17/9 + 1/9)

= 18/6 + 26/13 + 18/9

= 3 + 2 + 2 

=7

1/9 + 7/12 + 2/9 + 1/12 + 4/12 + 6/9

= (1/9 + 2/9 + 6/9) + (7/12 + 1/12 + 4/12)

= 9/9 + 12/12

= 1 + 1

=2

Answer 3

\(\left[\frac{1}{9}+\frac{2}{9}+\frac{6}{9}\right]+\left[\frac{7}{12}+\frac{1}{12}+\frac{4}{12}\right]=1+1=2\)