`a) (-3/25) : 6 = -1/50`
`b) (-4/17) . (-6 3/8) = (-4/17) . (-51/8) = 3/2`
`c) 2/3 . 5/2 - 3/4 . 2/3 = 2/3 . (5/2 - 3/4) = 2/3 . 7/4 = 7/6`
`d) 4 . 5 . (-4/9) = 20 . (-4/9) = -80/9`
`e) -5/23 : (-2) = 5/46`
`f) (-3 1/7) : (-1 6/49) = -22/7 : -55/49 = 14/5`
`g) 3/2 . 5/3 - 7/6 . 3/2 = 3/2 . (5/3 - 7/6) = 3/2 . 1/2 = 3/4`
`h) -7/11 . (-3 . 5) = -7/11 . -15 = 105/11`
`i) -17/13 . -4/65 . -8/31 = 68/845 . -8/31 = -544/26195`
`j) -15/4 . (-7/15) . (-2 2/5) = 7/4 . (-12/5) = -21/5`
`k) 12/25 . 23/7 - 12/7 . 13/25 = 276/175 - 156/175 = 120/175 = 24/35`
`l) -7/15 . 5/8 . 15/-7 . (-32) = [-7/15 . (15/-7)] . [5/8 . (-32)] = 1 . -20 = -20`