Решить уравнение: 12 * (1,3/4 Х+5/8) = - 6,1/2

12 * (1 3/4 х + 5/8) = - 6 1/2

1 3/4 х + 5/8 = - 6 1/2 : 12

7/4 х + 5/8 = - 13/2 * 1/12

7/4 х + 5/8 = - 13/24

7/4 х = - 13/24 - 5/8

7/4 х = - 13/24 - 15/24

7/4 х = - 28/24

х = - 28/24 : 7/4

х = - 28/24 * 4/7

х = - 28*4/24*7

х = - 4*4/24

х = - 16/24

х = - 2/3

проверка:

12 * (1 3/4 * (- 2/3) + 5/8) = - 6 1/2

12 * (- 7/4 * 2/3 + 5/8) = - 13/2

12 * (- 14/12 + 5/8) = - 13/2

12 * (- 84/72 + 45/72) = - 13/2

12 * (- 39/72) = - 13/2

- 39*12/72 = - 13/2

- 39/6 = - 13/2

- 13/2 = - 13/2