Question

Answer 1

Câu 4: 

=1+1=2

Answer 2

\(\dfrac{2}{7}+\dfrac{5}{14}+\dfrac{5}{7}+\dfrac{9}{14}=\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\left(\dfrac{5}{14}+\dfrac{9}{14}\right)=\dfrac{7}{7}+\dfrac{14}{14}=1+1=2\)

Answer 3

=\(\dfrac{4}{14}+\dfrac{5}{14}+\dfrac{10}{14}+\dfrac{9}{14}=2\)

Answer 4

=2