a)
`-3/4`. ( `-55/9`) . `8/11`
= `55/12` . `8/11`
= `10/3`
b) 1`4/23` + ( `5/21` - `4/23`) + `16/21` - `1/2`
= `27/23` + `5/21 - `4/23 + `16/21` - `1/2
= ( `27/23` - `4/23`) + ( `5/21` + `16/21) - `1/2`
= `23/23` + `21/21` - `1/2`
= 1 + 1 - `1/2`
= 2 - `1/2`
= `4/2` - `1/2`
= `3/2`
c)
`-3/8` . `6/13` + `7/13` . `-3/8` + 1`3/8`
= `-3/8` . `6/13` + `7/13` . `-3/8` + `11/8`
= `-3/8` . ( `6/13` + `7/13`) + `11/8`
= `-3/8` . `13/13` + `11/8`
= `-3/8 . 1 + `11/8`
= `-3/8` + `11/8`
= `8/8`
= `1`
d) 75% - ( `5/2` + `5/3`) + (`-1/2`)³
= `3/4` - `5/2` - `5/3` + `-1/8`
= ( `3/4` - `1/8`) + ( `5/2` - `5/3`)
= ( `6/8` - `1/8`) + ( `15/6` - `10/6`)
= `5/8` + `15/6`
=`25/8`