\(\dfrac{9}{7}+\dfrac{7}{13}-\left(\dfrac{7}{13}+\dfrac{2}{7}\right)\\ =\dfrac{9}{7}+\dfrac{7}{13}-\dfrac{7}{13}-\dfrac{2}{7}\\ =\dfrac{9}{7}-\dfrac{2}{7}\\ =\dfrac{7}{7}=1\)
`9/7 + 7/13 - (7/13 + 2/7)
`=9/7+7/13-7/13-2/7`
`=(9/7-2/7)+(7/13-7/13)`
`=7/7+0`
`=1`