1) 16 ⋅ 45 + 45 ⋅ 4 = 45 ⋅ (16 + 4) = 45 ⋅ 20 = 900
2) 16 ⋅ 45 - 45 ⋅ 6 = 45 ⋅ (16 - 6) = 45 ⋅ 10 = 450
3) -16 ⋅ 45 - 45 ⋅ 4 = -45 ⋅ (16 + 4) = -45 ⋅ 20 = -900
4) -16 ⋅ 45 + 45 ⋅ 6 = 45 ⋅ (-16 + 6) = 45 ⋅ (-10) = -450
5) -45 ⋅ 16 - 45 ⋅ 4 = -45 ⋅ (16 + 4) = -45 ⋅ 20 = -900
Ответ: 1) 900; 2) 450; 3) -900; 4) -450; 5) -900