:1,78x+0,84=1,34-0,72x 7,43-1,28x=1,42x+5 -4,29x+12,7=5,7-0,79x -3,32x-0,132=0,138+7,48x

1,78x+0,72x=1,34-0,84
2,5х = 0,5
х = 1\5 = 0,2  

7,43-1,28x=1,42x+5
-1,28х-1,42х = 5-7,43
-2,7х = -2,43
х = 0,9

-4,29x+12,7=5,7-0,79x 
-4,29х+0,79х =  = 5,7-12,7
-3,5х = -7
х = 2

-3,32x-0,132=0,138+7,48x
-3,32х-7,48х = 0,138+0,132
-10,8х = 0, 27
х = -0,025