a)
[tex]0.1x + 0.2 = - 0.3 | \times 10 \\ x + 2 = - 3 \\ x = - 5[/tex]
b)
[tex]0.25x + 0.4 = 0.35 | \times 100 \\ 25x + 40 = 35 \\ 25x = - 5 | \div 25 \\ x = - \frac{5}{25} = - \frac{1}{5} [/tex]
c)
[tex]1 - 0.2x = - 0.3x | \times 10 \\ 10 - 2x = - 3x \\ 10 = - x \\ x = - 10[/tex]
d)
[tex]0.01x - 1 = 0.1x - 0.1 | \times 100 \\ x - 100 = 10x - 10 \\ - 9x = 90 \\ x = - 10[/tex]
