Сравните произведения: a) 14⋅15 и 15⋅14; б) 2⋅3⋅4⋅5 и 6⋅21; в) 3⋅(4 + 12) и (4 + 8)⋅4; г) 7x и 0⋅x.

a) 14 × 15 = 210

15 × 14 = 210

210 = 210

б) 2 × 3 × 4 × 5 = 6 × 4 × 5 = 24 × 5 = 120

6 × 21 = 126

120 < 126

в) 3 × (4 + 12) = 3 × 16 = 48

(4 + 8) × 4 = 12 × 4 = 48

48 = 48

г) 7x и 0 × x.

Если x = 0, то 7 × 0 = 0 × 0

0 = 0

Если x = 1, то 7 × 1 = 7

0 × 1 = 0

7 > 0