`a) 3/4 . (5/6 - 1/4)`
`= 3/4 . (10/12 - 3/12)`
`= 3/4 . 7/12`
`= 7/16.`
`b) 1/4 + 3/4 . (-1/2 + 2/3)`
`= 1/4 + 3/4 . (-3/6 + 4/6)`
`= 1/4 + 3/4 . 1/6`
`= 1/4 + 1/8`
`= 2/8 + 1/8`
`= 3/8.`
`c) 8/15 . (-9/14) + 8/15 . (-5/14)`
`= 8/15 . [(-9/14) + (-5/14)]`
`= 8/15 . (-1)`
`= -8/15.`
`d) (-5/7) . 2/11 + (-5/7) . 9/11 + 1 5/7`
`= (-5/7) . (2/11 + 9/11) + 1 + 5/7`
`= (-5/7) . 1 + 1 + 5/7`
`= (5/7 - 5/7) + 1`
`= 1.`
`e) 2/5 - 3/4 - 1/2`
`= 8/20 - 15/20 - 10/20`
`= -17/20.`
`f) -3/7 + 5/13 + -4/7`
`= [(-3/7) + (-4/7)] + 5/13`
`= (-1) + 5/13`
`= -13/13 + 5/13`
`= -8/13.`
`g) (-4/5) . 1/2 + (-4/5) . 1/3 + (-4/5) . 1/4`
`= (-4/5) . (1/2 + 1/3 + 1/4)`
`= -4/5 . (6/12 + 4/12 + 3/12)`
`= -4/5 . 13/12`
`= -13/15.`
`h) 3 1/2 . 50%`
`= 7/2 . 1/2`
`= 7/4.`
`i) 11 3/13 - (2 4/7 + 5 3/13)`
`= 11 3/13 - 2 4/7 - 5 3/13`
`= (11 3/13 - 5 3/13) - 2 2/7`
`= 6 - 2 2/7`
`= 5 + 7/7 - 2 - 2/7`
`= (5 - 2) + (7/7 - 2/7)`
`= 3 5/7.`
