Завдання 401 - 500 » 436-437

436. Знайдіть добуток дробів: 1) 3/8 ∙ 8/11 = 3/11; 2) 5/7 ∙ 2/5 = 2/7; 3) 3/8 ∙ 8/15 = 3/15 = 1/5; 4) 11/27 ∙ 9/11 = 9/27 = 1/3. 437. Обчисліть: 1) 4/5 ∙ 15/16 = 3/4; 2) 10/13 ∙ 39/40 = 3/4; 3) 5/12 ∙ 6/25 = 1/(2 • 5) = 1/10; 4) 11/12 ∙ 4/33 = 1/(3 • 3) = 1/9; 5) 4/15 ∙ 25/28 = 5/(3 • 7) = 5/21; 6) 35/36 ∙ 54/55 = (7 • 3)/(2 • 11) = 21/22; 7) 9/14 ∙ 49/63 = (1 • 7)/(2 • 7) = 1/2; 8) 22/35 ∙ 63/121 = (2 • 9)/(5 • 11) = 18/55.