Завдання 1101 - 1200 » 1146

Обчисли: 1) 23/7 + (–31/2) – 59/14 = 23/7 + (–31/2) + (–59/14) = 23/7 + (–8(7 + 9)/14) = 23/7 + (–816/14)= – (88/7 – 23/7) = –65/7; 2) 42/9 – 51/18 – (–15/6) + (– 2/3) = 42/9 + (–51/18) + 15/6 + (–2/3) = 5(4 + 15)/18 + + (–5(1 + 12)/18) = 519/18 + (–513/18) = 6/18 = 1/3; 3) –31/2 + 4,8 – 8,7 – (–51/5) = –3,5 + 4,8 + (–8,7) + 5,2 = 10 + (–12,2) = –2,2; 4) 7,8 – 91/4 – 47/10 – (–3,4) = 7,8 + (–9,25) + (–4,7) + 3,4 = 11,2 + + (–13,95) = –2,75.