1.
(-18 1/4 + 17 5/6) * 8,4 + 6,5 = 3,
1) -18 1/4 + 17 5/6 = - 18 3/12 + 17 10/12 = - 17 15/12 + 17 10/12 = -5/12,
2) -5/12 * 8,4 = -5/12 * 84/10 = -7/2 = - 3 1/2 (или -3,5),
3) -3,5 + 6,5 = 3,
2.
2,4 + 5,6 * (13 3/4 + 12 13/14) = 152,
1) 13 3/4 + 12 13/14 = 13 21/28 + 12 26/28 = 25 48/28 = 26 20/28 = 26 5/7,
2) 5,6 * 26 5/7 = 56/10 * 187/7 = 1496/10 = 149,6 ,
3) 2,4 + 149,6 = 152