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