5.
[tex] \frac{1}{2} - \frac{x}{1} = \frac{1 - x}{3} \\ \frac{3}{6} - \frac{6x}{6} = \frac{2 - 2x}{6} \\ 3 - 6x = 2 - 2x \\ 3 - 2 = - 2x + 6x \\ 1 = 4x \\ x = \frac{1}{4 } \\ x = 0.25[/tex]
6.
[tex] \frac{3 - 2x}{4} = \frac{4}{5} \times ( \frac{75}{90} - \frac{75x}{100} ) \\ \frac{3 - 2x}{4} = \frac{4}{5} \times \frac{75}{90} - \frac{4}{5} \times \frac{75x}{100} \\ \frac{3 - 2x}{4} = \frac{2}{3} - \frac{3x}{5} \\ \frac{45 - 30x}{60} = \frac{40}{60} - \frac{36x}{60} \\ 45 - 30x = 40 - 36x \\ 45 - 40 = - 36x + 30x \\ 40 = - 6x \\ 6x = - 40 \\ x = - \frac {40}{6} [/tex]
