4)
`13/9` . `15/4` - `13/9` . `7/4` + `13/9` . `5/4` - `13/9`
=`13/9` . `15/4` - `13/9` . `7/4` + `13/9` . `5/4` - `13/9` . 1
= `13/9` . ( `15/4` - `7/4` + `5/4` - 1)
= `13/9` . 1
= `13/9`
5)
`2/3` - `1/3`( `x` - `1/4`) = 1`1/2` - `1/4`
`2/3` - `1/3` ( `x` - `1/4` ) = `3/2` - `1/4`
`2/3` - `1/3` ( `x` - `1/4` ) =`5/4`
`1/3` ( `x` - `1/4` ) = `2/3` - `5/4`
`1/3` ( `x` - `1/4`) = `-7/12`
( `x` - `1/4`) = `-7/12` : `1/3`
`x` - `1/4` = `-7/4`
`x` = `-7/4` + `1/4`
`x ` = `-3/2`