$\frac{a}{b + a}$
при a = 4, b = 2:
$\frac{a}{b + a} = \frac{4}{2 + 4} = \frac{4}{6} = \frac{2}{3}$
при a = −10, b = 20:
$\frac{a}{b + a} = \frac{-10}{20 - 10} = \frac{-10}{10} = -1$
при a = 6, b = −5:
$\frac{a}{b + a} = \frac{6}{-5 + 6} = \frac{6}{1} = 6$
при a = 0, b = 7:
$\frac{a}{b + a} = \frac{0}{7 + 0} = \frac{0}{7} = 0$
при a = −1, b = 0:
$\frac{a}{b + a} = \frac{-1}{0 - 1} = \frac{-1}{-1} = 1$
при $a = -\frac{1}{2}$, b = −2:
$\frac{a}{b + a} = \frac{-\frac{1}{2}}{-2 - \frac{1}{2}} = \frac{-\frac{1}{2}}{-2\frac{1}{2}} = \frac{1}{2} * \frac{2}{5} = \frac{1}{5}$
при a = −0,7, b = 1,4:
$\frac{a}{b + a} = \frac{-0,7}{1,4 - 0,7} = \frac{-0,7}{0,7} = -1$