`e,`
`(-3)/5 . 5/7 + (-3)/5 . 3/7 + (-3)/5 . 6/7`
`= (-3)/5 . (5/7 + 3/7 + 6/7)`
`= (-3)/5 . 2`
`= (-6)/5`
`f,`
`1/3 . 4/5 + 1/3 . 6/5 - 4/3`
`= 1/3 . 4/5 + 6/5 - 1/3 . 4`
`= 1/3 . (4/5 + 6/5 - 4)`
`= 1/3 . (-2)`
`= (-2)/3`
`g,`
`4/19 . (-3)/7 + (-3)/7 . 15/19 + 5/7`
`= (-3)/7 . (4/19 + 15/19) + 5/7`
`= (-3)/7 . 1 + 5/7`
`= (-3)/7 + 5/7`
`= 2/7`
`h,`
`5/9 . 7/13 + 5/9 . 9/13 - 5/9 . 3/13`
`= 5/9 . (7/13 + 9/13 - 3/13)`
`= 5/9 . 1`
`= 5/9`