$$(a + 6882) : 28 = 2660$$ $$a + 6882 = 2660 \cdot 28$$ $$a + 6882 = 74480$$ $$a = 74480 - 6882$$ $$a = 67598$$
$$(14289 - b) \cdot 404 = 4242000$$ $$14289 - b = 4242000 : 404$$ $$14289 - b = 10500$$ $$b = 14289 - 10500$$ $$b = 3789$$
Ответ: a) a = 67598; б) b = 3789