$\frac{x}{2}$
при x = 0:
$\frac{x}{2} = \frac{0}{2} = 0$
при x = −2:
$\frac{x}{2} = \frac{-2}{2} = -$
при $x = 2^3$:
$\frac{x}{2} = \frac{2^3}{2} = 2^2 = 4$

$\frac{10}{x}$
при x = 0:
$\frac{10}{x} = \frac{10}{0}$ − не имеет смысла
при x = −2:
$\frac{10}{x} = \frac{10}{-2} = -5$
при $x = 2^3$:
$\frac{10}{x} = \frac{10}{2^3} = \frac{5}{2^2} = \frac{5}{4} = 1,25$

$\frac{2 - 3x}{7x}$
при x = 0:
$\frac{2 - 3x}{7x} = \frac{2 - 3 * 0}{7 * 0} = \frac{2}{0}$ − не имеет смысла
при x = −2:
$\frac{2 - 3x}{7x} = \frac{2 - 3 * (-2)}{7 * (-2)} = \frac{2 + 6}{-14} = -\frac{8}{14} = -\frac{4}{7}$
при $x = 2^3$:
$\frac{2 - 3x}{7x} = \frac{2 - 3 * 2^3}{7 * 2^3} = \frac{2(1 - 3 * 2^2)}{7 * 2^3} = \frac{1 - 3 * 4}{7 * 2^2} = \frac{-11}{7 * 4} = -\frac{11}{28}$

$\frac{x - 2}{2 - 3x}$
при x = 0:
$\frac{x - 2}{2 - 3x} = \frac{0 - 2}{2 - 3 * 0} = \frac{-2}{2} = -1$
при x = −2:
$\frac{x - 2}{2 - 3x} = \frac{-2 - 2}{2 - 3 * (-2)} = \frac{-4}{2 + 6} = -\frac{4}{8} = -\frac{1}{2}$
при $x = 2^3$:
$\frac{x - 2}{2 - 3x} = \frac{2^3 - 2}{2 - 3 * 2^3} = \frac{8 - 2}{2 - 3 * 8} = \frac{6}{2 - 24} = \frac{6}{-22} = -\frac{3}{11}$