Решением уравнения (90+15*(5x+177)):45=66
(90 + 15 * (5x+ 177)) : 45 = 66 90 + 75x + 2655) : 45 = 66 75x + 2745 = 45 * 66 75x + 2745 = 2970 75x = 2970 - 2745 75x = 225 x = 3