Ответ:
\(3574 \cdot 742 = 3574 \cdot (700 + 40 + 2) = 2\,501\,800 + 142\,960 + 7\,148 = 2\,651\,908\).
\(6405 \cdot 907 = 6405 \cdot (900 + 7) = 5\,764\,500 + 44\,835 = 5\,809\,335\).
\(2218 \cdot 2244 = 2218 \cdot (2200 + 44) = 4\,879\,600 + 97\,592 = 4\,977\,192\).
\(3004 \cdot 5005 = 3004 \cdot (5000 + 5) = 15\,020\,000 + 15\,020 = 15\,035\,020\).
Ответ: а) 2 651 908; б) 5 809 335; в) 4 977 192; г) 15 035 020.
