1) (1 2/7у - 1/2) : 2,5 = 5,2;1 2/7у - 1/2 = 5,2 * 2,5;1 2/7у - 1/2 = 13;1 2/7у = 13 + 1/2;1 2/7у = 13 1/2;у = 13 1/2 : 1 2/7;у = 27/2 : 9/7;у = 27/2 * 7/9;у = 3/2 * 7/1;у = 21/2;у = 10 1/2.Ответ: у = 10 1/2.2) 22 * (17/26 х - 3/4)= 5 1/13;17/26х - 3/4 = 5 1/13 : 22;17/26х - 3/4 = 66/13 : 22/1;17/26х - 3/4 = 66/13 * 1/22;17/26х - 3/4 = 3/13 * 1/1;17/26х - 3/4 = 3/13;17/26х = 3/13 + 3/4;17/26х = 12/52 + 39/52;17/26х = 51/52;х = 51/52 : 17/26;х = 51/52 * 26/17;х = 3/2 * 1/1;х = 3/2;х = 1 1/2.Ответ: х = 1 1/2.