Завдання 139 - 300 » 285

Спростіть вираз: 1) 12a2 ∙ 5a3b7 = 60a5b7; 3) 3ab ∙ (–17a2b) = –51a3b2; 2) –4m3 ∙ 0,25m6 = –m9; 4) 56x5y14 ∙ 2/7x2y = 16x7y15; 5) –1/3p2 ∙ (–27k) ∙ 5pk = 45p3k2; 6) 21/4b2c5d3 ∙ (–31/3b3c4d7) = –9/4b2c5d3 ∙ 10/3b3c4d7 = –7,5b5c9d10.