Завдання 401 - 500 » 448

Обчисліть: 1) (1/2 + 1/4) ∙ 4/9 = (2/4 + 1/4) ∙ 4/9 = 3/4 ∙ 4/9 = (1 • 1)/(1 • 3) = 1/3; 2) (1/2 – 1/6) ∙ 15/16 = (3/6 – 1/6) ∙ 15/16 = 2/6 ∙ 15/16 = (1 • 5)/(2 • 8) = 5/16; 3) 8/11 ∙ (3/8 – 1/4) = 8/11 ∙ (3/8 – 2/8) = 8/11 ∙ 1/8 = (8 • 1)/(11 • 8) = 2/11.