3/7+2/5 2. 4/21+1. 9/14помогите пожайлуста
3/7+2/5=15/35+14/35=29/35
2. 4/21+ 1. 9/14=46/21+ 23/14=92/42+69/42=161/42=3. 35/42=3. 5/6