1) $$2801 \cdot 640 = 1792640$$
2) $$1792640 - 1789631 = 3009$$
3) $$95823 : 189 = 507$$
4) $$775 - 507 = 268$$
5) $$3009 \cdot 268 = 806412$$
6) $$1630314 : 798 = 2043$$
7) $$806412 + 2043 = 808455$$
Ответ: 808455