(x+4/12)-4/15=16/35 Помогите решить...

(х + 4/21) - 4/15 = 16/35х + 4/21 = 16/35 + 4/15 = 48/105 + 28/105 = 76/105х = 76/105 - 4/21 = 76/105 - 20/105 = 56/105х = 56/105Проверка: (56/105 + 20/105) -  28/105 = 76/105 - 28/105 = 48/105 = 16/35Ответ: х = 56/105