[tex] \frac{1}{3} x + 2 = \frac{2}{3} (5x - 1) \\ \frac{1}{3} x + 2 = \frac{10}{3} x - \frac{2}{3} | \times 3 \\ x + 6 = 10x - 2 \\ - 9x = - 8 \\ x = \frac{8}{9} [/tex]
[tex]x - \frac{3}{7} (2x + 3) = \frac{2}{7} x \\ x - \frac{6}{7} x + \frac{9}{7} = \frac{2}{7} x | \times 7 \\ 7x - 6x + 9 = 2x \\ - x = - 9 \\ x = 9[/tex]
[tex]4x(2 + x) = (2x - 1 {)}^{2} \\ 8x - 4 {x}^{2} = 4 {x}^{2} - 4x + 1 \\ 8x = - 4x + 1 \\ 12x = 1 \\ x = \frac{1}{12} [/tex]
