Вправи для повторення розділу 1 » 37

35. Обчисли значення виразу: 2/(1 ∙ 3) + 2/(3 ∙ 5) + 2/(5 ∙ 7) + … + 2/(17 ∙ 19) = (1/1 – 1/3) + (1/3 – 1/5) + (1/5 – 1/7) + … + (1/17 – 1/19) = 1 – 1/3 + 1/3 – 1/5 + 1/5 – 1/7 + … + 1/17 – 1/19 = 1 – 1/19 = 18/19. 36. Обчисли: 1) 92/3 + 2 = (29 + 6)/3 = 35/3 = 112/3; 2) 7 + 32/11 = 102/11; 3) 11/12 + 1/4 = (13 + 3)/12 = 16/12 = 11/3; 4) 74/15 + 1/5 = (109 + 3)/15 = 112/15 = 77/15; 5) 121/3 – 2 = (37 - 6)/3 = 31/3 = 101/3; 6) 4 – 15/13 = (52 - 18)/13 = 34/13 = 28/13; 7) 71/4 – 1/16 = (116 - 1)/16 = 115/16 = 73/16; 8) 47/20 – 1/4 = (87 - 5)/20 = 82/20 = 41/10;