a) 3 `14/19` + `13/17` + `35/43` + 6 `5/19` + `8/43`
= `71/19` + `13/17` + `35/43` + `119/19` + `8/43`
= ( `71/19` + `119/19` ) + ( `35/43` + `8/43`) + `13/17`
= `190/19` + `43/43` + `13/17`
= `10` + `1` + `13/17`
= `11` + `13/17`
= `77/7` + `13/17`
= `90/17`