Ответ:

  1. а) ✓ 57 × 1000 × 3 = 171 000; ✓ 57 × 3 × 1000 = 171 000.
  2. б) ✓ 1000 × 5 × 42 = 210 000; ✓ 42 × 5000 = 210 000; ✓ 42 × 5 × 1000 = 210 000.
  3. в) ✓ 33 × 1000 × 3 = 99 000; ✓ 33 × 3000 = 99 000.
  4. г) ✓ 40 × 7 × 1000 = 280 000; ✓ 7 × 40 × 10 × 100 = 280 000.