(410 - d) / 7 + 70 = 120
(410 - d) / 7 = 50 (120 - 70)
410 - d = 350 (50 * 7)
-d = 350 - 410
-d = -60
d = 60
(410 - 60) / 7 + 70 = 120
350 / 7 + 70 = 120
50 + 70 = 120
120 = 120
ответ: 60
