Вправи: 4

4. Чому дорівнює значення виразу:

1) 18512 – 712 ∙ 11921 – 1772 ∙ 23 = 18512 – 712 ∙ 4021 – 1772 ∙ 23 = 18512 = 1 • 103 • 3 – 17 • 136 • 3 = 185\912 – 11129 – 17108 = 1745 - 12 - 17108 = 1716108 = 17427;

2) (634 – 518 : 1932) ∙ 511 = (634 – 418 : 4132) ∙ 511 = (634 – 418 ∙ 3241) ∙ 511 =

= (634 – 4) ∙ 511 = 234 ∙ 511 = 114 ∙ 511 = 114;

3) (–1,42 – (–3,22)): (–0,4) + (–6) ∙ (–0,7) = (–1,42 + 3,22) : (–0,4) + 4,2 = 1,8 : (–0,4) + 4,2 = –4,5 + 4,2 = –0,3;

4) (–7\218 + 11\312) : (–1948) = – -14+3336 ∙ 4819 = – 19 • 4836 • 19 = – 43 = –113;

5) (–31\512 – 21\415) : (–5320) = –55+460 : (–10320) = 5960 ∙ 20103 = 309 • 2060 • 103 = 1.