\[1)\ \left\{ \begin{matrix} y = \cos\frac{x}{2}\text{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ } \\ y = - x^{2} + 6x - 8 \\ \end{matrix} \right.\ \]
\[y = - x^{2} + 6x - 8\]
\[x_{0} = - \frac{6}{2 \bullet ( - 1)} = \frac{6}{2} = 3;\]
\[y_{0} = - 9 + 18 - 8 = 1.\]
\[Ответ:\ \ 2\ решения.\]
\[2)\ \left\{ \begin{matrix} y = \cos x\text{\ \ } \\ y = \log_{7}x \\ \end{matrix} \right.\ \]
\[Ответ:\ \ 3\ решения.\]