`3,5 . (-1 2/5)=7/2 . (-7/5)=-49/10`
$\\$
`1,25 . (-3 3/8)=5/4 . (-27)/8=-135/32`
$\\$
`(-3,5):(-2 3/5)=-7/2:(-13/5)=-7/2 . (-5/13)=35/26`
$\\$
`2/15:(-5 4/5) . 2 5/12`
`=2/15 : (-29/5) . 29/12`
`=2/15 .(-5/29) . 29/12`
`=-1/18`
$\\$
`(2 2/15 . 9/17 . 3/32) :(-3/17)`
`=(32/15 . 9/17 . 3/32) . (-17/3)`
`=9/85 . (-17/3)`
`=-3/5`
$\\$
`[(1/9:8/27):1/3]:81/128`
`=[3/8:1/3] . 128/81`
`=9/8 . 128/81`
`=16/9`
$\\$
`13 2/7:(-8/9):2 5/7: (-8)/9`
`=93/7 . (-9/8) . 19/7 . (-9)/8`
`=7533/1216`
