


\[\boxed{\mathbf{857\ (857).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[= \frac{1}{3} \cdot \left( \frac{1}{a} - \frac{1}{a + 12} \right) =\]
\[= \frac{a + 12 - a}{3a \cdot (a + 12)} = \frac{4}{a \cdot (a + 12)}\]

\[\boxed{\mathbf{8}\mathbf{5}\mathbf{7}\mathbf{\text{.\ }}Еуроки\ - \ ДЗ\ без\ мороки}\]
\[y = - 2x + 4\]
| \[x\] | \[0\] | \[2\] | \[3\] |
|---|---|---|---|
| \[y\] | \[4\] | \[0\] | \[- 2\] |

\[1)\ нуль\ функции:x = 2;\]
\[2)\ y > 0\ при\ x \in ( - \infty;2);\]
\[3)\ \text{M\ }( - 36;68):\ \]
\[68 = - 2 \cdot ( - 36) + 4\]
\[68 \neq 76\]
\[график\ не\ проходит\ через\ \]
\[( \cdot )M.\]