1) 25 ⋅ 78 ⋅ 4; 4) 49 ⋅ 9 + 21 ⋅ 9; 2) 2 ⋅ 49 ⋅ 50; 5) 316 ⋅ 5 − 216 ⋅ 5.
3) 3 ⋅ 5 ⋅ 8 ⋅ 3 6) 239 ⋅ 47 + 239 ⋅ 53.

7800, 4900, 360, 630, 500, 2390

Пошаговое объяснение:

1) 25×78×4 = 100×78 = 7800

2) 2×49×50 = 100×49 = 4900

3) 3×5×8×3 = 3×40×3 = 120×3 = 360

4) 49×9+21×9 = 441+189 = 630

5) 316×5-216×5 = 1580-1080 = 500

6) 239×47+239×53 = 239×100 = 23900