690. Решите уравнение x - x/9 = -26/9.

690. $x - \frac{x}{9} = -\frac{26}{9}$ | $\frac{8x}{9} = -\frac{26}{9}$ | $8x = -26$ | $x = -\frac{26}{8} = -3,25$. 691. $x + \frac{x}{3} = -12$ | $\frac{4x}{3} = -12$ | $4x = -36$ | $x = -9$. 692. $x + \frac{x}{2} = -12$ | $\frac{3x}{2} = -12$ | $3x = -24$ | $x = -8$. 693. $x + \frac{x}{3} = 8$ | $\frac{4x}{3} = 8$ | $4x = 24$ | $x = 6$. 694. $x + \frac{x}{7} = -8$ | $\frac{8x}{7} = -8$ | $8x = -56$ | $x = -7$. 695. $x + \frac{x}{2} = -6$ | $\frac{3x}{2} = -6$ | $3x = -12$ | $x = -4$. 696. $x + \frac{x}{2} = \frac{9}{2}$ | $\frac{3x}{2} = \frac{9}{2}$ | $3x = 9$ | $x = 3$. 697. $x + \frac{x}{5} = -\frac{24}{5}$ | $\frac{6x}{5} = -\frac{24}{5}$ | $6x = -24$ | $x = -4$. 698. $x + \frac{x}{12} = \frac{13}{2}$ | $\frac{13x}{12} = \frac{13}{2}$ | $x = \frac{13}{2} \cdot \frac{12}{13} = 6$. 699. $x + \frac{x}{10} = -\frac{11}{2}$ | $\frac{11x}{10} = -\frac{55}{10}$ | $11x = -55$ | $x = -5$. 700. $x + \frac{x}{12} = -\frac{13}{4}$ | $\frac{13x}{12} = -\frac{39}{12}$ | $13x = -39$ | $x = -3$. 701. $\frac{x}{7} + \frac{x}{2} = \frac{18}{7}$ | $\frac{2x + 7x}{14} = \frac{36}{14}$ | $9x = 36$ | $x = 4$.