Сделайте вычитание: 1) 7/8(3/10) 2)11/1217/18 3)3/79/14 4)5/9(3/4) 5)311/12(44/9) 6)45/176 7)13/831/4 8)214/15119/45

Приведем к общему знаменателю и вычислим:

1) 7/8 - (-3/10) = 7/8 + 3/10 = (7 * 5)/40 + (3 * 4)/40 = 35/40 + 12/40 = 47/40 = 1 7/40;

2) 11/12 - 17/18 = (11 * 3)/36 - (17 * 2)/36 = 33/36 - 34/36 = -1/36;

3) -3/7 - 9/14 = (-3 * 2)/14 - 9/14 = -6/14 - 9/14 = -15/14 = -1 1/14;

4) -5/9 - (-3/4) = -5/9 + 3/4 = (-5 * 4)/36 + (3 * 9)/36 = -20/36 + 27/36 = 7/36;

5) 311/12 - (-44/9) = (311 * 3)/36 + (44 * 4)/36 = 933/36 + 176/36 = 1109/36 = 30 29/36;

6) 45/17 - 6 = 45/17 - (6 * 17)/17 = 45/17 - 102/17 = -57/17 = -3 6/17;

7) 13/8 - 31/4 = 13/8 - (31 * 2)/8 = 13/8 - 62/8 = -49/8 = -6 1/7;

8) -214/15 - 119/45 = (-214 * 3)/45 - 119/45 = -642/45 - 119/45 = -761/45 = -16 21/45;

9) -31/6 - (-11/4) = (-31 * 2)/12 + (11 * 3)/12 = -62/12 + 33/12 = -29/12 = -2 5/12.