1) 5.7X - 2.1X = - 4.8 - 7.2
3.6X = - 12
X = ( - 12 ) : 3.6 = ( -60\18) = ( - 3 целых 1\3)
2) 0.4X - 2 - 1.5X - 1 = 2.8 + 4X
- 1.1X - 3 = 2.8 + 4X
- 5.1X = 5.8
X = 5.8 : ( - 5.1) = ( - 29\5 : 51\10) = ( - 290\255) = ( - 1 целая 35\255) =
= ( - 1 7\51)
3) 1.2 - 4X = - 6X - 2.1 = - 2.4
- 4X + 6X = - 2.1 + 1.2 = - 2.4
условие не поняла - напиши, дорешаю))