( 2,5 -3 целых одна вторая ) 0,5 = 2(ОДНА

1

(2,5 - 3 1/2) : 0,5 = (25/10 - 7/2) : 5/10 = (25/10 - (7 * 5)/(2 * 5)) : 5/10 = (25/10 - 35/10) : 5/10 = 10/10 : 5/10 = 1/1 : 5/10 = 1/1 * 10/5 = 1 * 2 = 2.

2

2 * (1/3 + 2 4/6) = 2 * (1/3 + 16/6) = 2 * ((1 * 2)/(3 * 2) + 16/6) = 2 * (2/6 + 16/6) = 2 * 18/6 = 2 * 3 = 6.

3

(3,6 - 3 1/3) * 0,3 = (36/10 - 10/3) * 3/10 = (18/5 - 10/3) * 3/10 = ((18 * 3)/(5 * 3) - (10 * 5)/(3 * 5)) * 3/10 = (54/15 - 50/15) * 3/10 = 4/15 * 3/10 = 2/5 * 1/5 = 2/25.

0,7 * (2х - 5) = 2,2 - 2 * (0,3х + 7,25);

0,7 * 2х + 0,7 * (-5) = 2,2 - 2 * 0,3х - 2 * 7,25;

1,4х - 3,5 = 2,2 - 0,6х - 14,5;

1,4х + 0,6х - 3,5 = 2,2 - 14,5;

2х - 3,5 = -12,3;

2х = -12,3 + 3,5;

2х = -8,8;

х = -8,8 : 2;

х = -4,4.

Ответ: х = -4,4.