1) 3/4+1/5=15/20+4/20= 19/20
2) 5/8+ 1/6= 15/24+ 4/24= 19/24
3) 7/12+ 4/5= 35/60+ 48/60= 83/60= 1 23/60
4) 9/14+ 2/21= 27/42+ 4/42= 31/42
5) 2/9+ 4/15= 10/45+ 12/45= 22/45
6) 21/100+ 3/10= 21/100+ 30/100= 51/100
7) 12/18+ 5/60= 120/180+ 15/180= 135/180= 3/4
8) 4/24+ 3/36= 12/72+ 6/72= 18/72=1/4