0,8x+1,4=0,4x-2,6 0,18x-3,54=0,19x-2,89 2 2/3x+3 2/15 = 3 1/5x+2 1/3

1)
0.8x+1.4 =0.4x -2.6
0.8x -0.4x = -2.6 -1.4
0.4x = -4
x= -4/0.4
x = -10

2)
0.18x -3.54 =0.19x -2.89
0.18x -0.19x = -2.89 +3.54
-0.01x =0.65
x = -65

3)
2 2/3 =8/3
3 2/15 =47/15
3 1/5 =16/5
2 1/3 =7/3

8/3x +47/15 =16/5x +7/3
8/3x -16/5x =7/3 -47/15
(8*5 -16*3)/15x =(7*5-47)/15
(40-48)/15x =(35-47)/15
-8/15x = -12/15
x =12/15 : 8/15
x =12/15 * 15/8
x =(12*15)/(15*8)
x =12/8
x =3/2
x =1.5