(5y+21):26=16 Срочно
(5у+21):26=16 (5у+21)=16*26 5у+21=416 5у=416-21 5у=395 у=395:5 у=79
5у + 21 = 16 * 26, 5у + 21 = 416, 5у = 416 - 21, 5у = 395, у = 395 : 5, у = 79