Решите примеры,только подробно: 1/2+1/3= 1/4+2/5= 2/3+1/4= 3/4+2/4= 5/7-1/6= 3/4-1/3= 1/8+1/4= 2/3-5/9= 1/2-5/12= 5/12-2/9= 1/8+7/12= 3/4-1/6= 5/9+3/4= 23/40-3/8= 9/35-9/28=

1/2+1/3=3/6+2/6=5/6
1/4+2/5=5/20+8/20=13/20
2/3+1/4=8/12+3/12=11/12
3/4+2/4=5/4=1 1/4