Сравниваем выражения:
1) 18 \(\cdot\) 20 + 18 \(\cdot\) 3 ☐ 18 \(\cdot\) 23
Представим 18 \(\cdot\) 23 как 18 \(\cdot\) (20 + 3) = 18 \(\cdot\) 20 + 18 \(\cdot\) 3
Тогда 18 \(\cdot\) 20 + 18 \(\cdot\) 3 = 18 \(\cdot\) 23
2) 13 \(\cdot\) (40 + 6) ☐ 13 \(\cdot\) 40 + 13
13 \(\cdot\) (40 + 6) = 13 \(\cdot\) 40 + 13 \(\cdot\) 6
Следовательно, 13 \(\cdot\) (40 + 6) > 13 \(\cdot\) 40 + 13