Дробь4/7+5/6 и 5/12+2/15
4/7+5/6=24/42+35/42=69/42=23/14=1. 9/14 5/12+2/15=75/180+24/180=99/180=11/20
4/7+5/6=24+35/42=59/42 5/12+2/15=25+8/60=33/60=11/20