помогите решить уравнение (-31/21 х + 5/7) - 1/3 = - 18/7

(-31/21 х + 5/7) - 1/3 = - 18/7

-31/21 х + 15/21 - 7/21 = - 54/21

-31/21 х=-54/21 - 15/21 + 7/21

-31/21 х = - 62/21

х = - 62/21 : - 31/21

х=-21/21 * (-21/31)

х=2

Проверка:

((-31/21) * 2 + 5/7) - 1/3=-18/7

-62/21 + 5/7 - 1/3 = - 18/7

-62/21+15/21-7/3=-18/7

-62/21 + 15/21 - 7/21=-18/7

-54/21=-18/7

-18/7=-18/7

(-31/21 х+5/7) - 1/3 = - 18/7

-31/21 х+5/7 = - 18/7+1/3

-31/21 х+5/7 = - 54/21+7/21

-31/21 х+5/7 = - 47/21

-31/21 х = - 47/21-5/7

-31/21 х = - 47/21-15/21

-31/21 х = - 62/21

х = - 62/21: (-31/21)

х = - 62/21 * (-21/31)

х = 2

Проверяем:

(-31/21*2+5/7) - 1/3 = (-62/21+15/21) - 1/3 = - 47/21-1/3 = - 47/21-7/21 = - 54/21 =

= 18/7

Ответ: 2.