выполни сложения дробей 2/5+7/15;2/7+1/3;5/6+7/8;5/18+2/3

2/5+7/5=6/15+7/15=13/15
2/7+1/3=6/21+7/21=13/27
5/6+7/8=40/48+42/48=82/48=1 17/24
5/18+2/3=10/36+24/36=34/36=17/18