a, `11/9` . `3/4` - `2/9` . `3/4`
= ( `11/9` - `2/9` ) . `3/4`
= `9/9` . `3/4`
= 1 . `3/4`
= `3/4`
b, `(-5)/4` + `3/7` . `21/8`
= `(-5)/4` + `9/8`
= `(-10)/8` + `9/8`
= `(-1)/8`
c, `2019^0` . √`25/9` + 3 . | -0,25 |
= 1 . `5/3` + 3 . ( 0,25 )
= `5/3` + 0,75
= `5/3` + `3/4`
= `20/12` + `9/12`
= `29/12`