`2/5 + 3/7 =`
`(2 xx 7+5 xx 3)/(5 xx 7) = ` `29/35`
`2/3 + 4/5 =`
`(2 xx 5 + 3 xx 4)/(3 xx 5)` `= 22/15`
`4/5 - 2/3 =`
`(4 xx 3 - 5 xx 2)/(5 xx 3)` `=2/15`
`3/4 - 2/9 =`
`(3 xx 9 - 4 xx 2)/(4 xx 9)` `= 19/36`
`4/9 + 5/7 =`
`(4 xx 7 + 9 xx 5)/(9 xx 7)` `= 73/63`
`5/8 + 3/4 =`
`(5 xx 4 + 8 xx 3)/(8 xx 4)` `= 44/32`
`4/5 - 3/7 =`
`(4 xx 7 - 5 xx 3)/(5 xx 7)` `= 13/35`
`2/3 - 5/8 =`
`(2 xx 8 - 3 xx 5)/(3 xx 8)` `=1/24`