Question

\(\dfrac{2}{9}\) + \(\dfrac{3}{7}\) + \(\dfrac{4}{7}\) - \(\dfrac{2}{13}\) + \(\dfrac{7}{9}\) 

tính nhanh ( ghi chi tiết giúp mk ạ)

Answer 1

=-2/13

Answer 2

\(=\left(\dfrac{2}{9}+\dfrac{7}{9}\right)+\left(\dfrac{3}{7}+\dfrac{4}{7}\right)-\dfrac{2}{13}\)

\(=1+1-\dfrac{2}{13}=2-\dfrac{2}{13}=\dfrac{26}{13}-\dfrac{2}{13}=\dfrac{24}{13}\)

Answer 3

= ( 2/9 + 7/9 ) + ( 3/7 + 4/7 ) - 2/13

= 1 + 1 - 2/13

= 2-2/13

= 26/13 - 2/13 = 23/13

Answer 4

2/9 + 3/7 + 4/7 - 2/13 + 7/9

= (2/9 + 7/9) + ( 3/7 + 4/7 ) - 3/13

=       1          +        1          - 3/13

=                        2               - 3/13

=                  23/13

Answer 5

`#hungg`

\(\dfrac{2}{9}+\dfrac{3}{7}+\dfrac{4}{7}-\dfrac{2}{13}+\dfrac{7}{9}\\ =\left(\dfrac{2}{9}+\dfrac{7}{9}\right)+\left(\dfrac{3}{7}+\dfrac{4}{7}\right)-\dfrac{2}{13}\\ =\dfrac{9}{9}+\dfrac{7}{7}-\dfrac{2}{13}\\ =1+1-\dfrac{2}{13}\\ =2-\dfrac{2}{13}\\ =\dfrac{26}{13}-\dfrac{2}{13}\\ =\dfrac{24}{13}\)

Answer 6

=1+1−2/13=2−2/13=26/13−2/13=24/13