3,41y+5,86y-7,69y=13,43
3,41у + 5,86у - 7,69у = 13,43 1,58у = 13,43 у = 13,43 : 1,58 у = 8,5 Проверка: (3,41 + 5,86 - 7,69) * 8,5 = 13,43 1,58 * 8,5 = 13,43 13,43 = 13,43
1,58у=13,43 у=13,43/1,58 у=8,5