8)
[tex] \frac{ \frac{x}{2} }{5} = \frac{x}{10} [/tex]
[tex] \frac{x}{ \frac{2}{5} } = \frac{5x}{2} = \frac{25x}{10} [/tex]
[tex] \frac{26x}{10} = 13[/tex]
[tex]x = 5[/tex]
9)
[tex]2x = \frac{6x}{3} [/tex]
[tex] \frac{6x}{3} + ( \frac{7x - 1}{3} ) = \frac{38}{3} [/tex]
[tex] \frac{13x - 1}{3} = \frac{38}{3} [/tex]
[tex]x = 3[/tex]