(5/21+2/15)+2/21= (2/35+3/28)+1/28= (7/30+8/45)+(2/45+1/30)= (5/24+11/60)+(13/60+1/24)=

Question

(5/21+2/15)+2/21= (2/35+3/28)+1/28= (7/30+8/45)+(2/45+1/30)= (5/24+11/60)+(13/60+1/24)=

Answer 1

1) 7/21+2/15=(7*15+2*21)/315=147/315

2) 2/35+4/28=2/35+5/35=1/5

3) 8/30+10/45=(8*1,5+10)/45=22/45

4) 6/24+24/60=1/4+6/15=(15+6*4)/60=39/60