Завдання 1301 - 1401 » 1331

Обчисліть: (1 + 1/2) ∙ (1/3 – 1) ∙ (1 + 1/4) ∙ (1/5 – 1) ∙ (1 + 1/6) ∙ (1/7 – 1) ∙ (1 + 1/8) ∙ (1/9 – 1) = 3/2 ∙ (–2/3) ∙ 5/4 ∙ (–4/5) ∙ 7/6 ∙ (–6/7) ∙ 9/8 ∙ (–8/9) = (–1) ∙ (–1) ∙ (–1) ∙ (–1) = 1.