`6 / 28 - 5 / [-2] - 2`
`= 3 / 14 + 35 / 14 - 28 / 14`
`= 10 / 14 = 5 / 7`
\(=\dfrac{6}{28}+\dfrac{5}{2}-2\)
\(=\dfrac{19}{7}-2\)
\(=\dfrac{5}{7}\)
\(\dfrac{6}{28}-\dfrac{5}{-2}-2=\dfrac{3}{14}+\dfrac{5}{2}-2=\dfrac{19}{7}-2=\dfrac{5}{7}\)
=\(\dfrac{3}{14}\)-\(\dfrac{-35}{14}\)-\(\dfrac{28}{14}\)=\(\dfrac{10}{14}\)=\(\dfrac{5}{7}\)