(6y+14)/2+15=40
3у + 7 + 15 = 40 3у = 40 - 22 3у = 18 у = 18: 3 у = 6
(6y+14)/2=40-15 (6y+14)/2=25 6y+14=25·2 6y+14=50 66y=50-14 6y=36 y=36/6 y=6 ОТВЕТ: 6