Ответ:

[tex]1)0.3(5x - 7) - 3(0.2x + 3.2) = 0 \\ 1.5x - 2.1 - 0.6x - 9.6 = 0 \\ 0.9x - 11.7 = 0 \\ 0.9x = 11.7 \\ x = 13 \\ \\ 2)3(0.4x + 7) - 4(0.8x - 3) = 2 \\ 1.2x + 21 - 3.2x + 12 - 2 = 0 \\ - 2 x + 31 = 0 \\ - 2x = 31 \\ x = - 15.5 \\ \\ 3)[/tex]

3)0,7х-1,82-0,8х=3,46

-0,1х=5,28

х=. -52,8