Сподробным решением! найти f(a), если: f(x)=3x^3-2x+4 a= 1 -2; 0 3

[tex]a^{2}=\left[\begin{array}{cc}1& -2\\0& 3\end{array}\right] \cdot\left[\begin{array}{cc}1& -2\\0& 3\end{array}\right] =\left[\begin{array}{cc}1\cdot1-2\cdot0& 1\cdot(-2)-2\cdot3\\0\cdot1+3\cdot0& 0\cdot(-2)+3\cdot3\end{array}\right] =\left[\begin{array}{cc}1&
-8\\0& 9\end{array}\right][/tex]

[tex]a^{3}=\left[\begin{array}{cc}1& -2\\0& 3\end{array}\right] \cdot\left[\begin{array}{cc}1& -2\\0& 3\end{array}\right] \cdot\left[\begin{array}{cc}1& -2\\0& 3\end{array}\right] =\left[\begin{array}{cc}1& -8\\0&
9\end{array}\right] \cdot \left[\begin{array}{cc}1& -2\\0& 3\end{array}\right] =\\\\ \left[\begin{array}{cc}1\cdot1-8\cdot0& 1\cdot(-2)-8\cdot3\\0\cdot1+9\cdot0& 0\cdot(-2)+9\cdot3\end{array}\right] =\left[\begin{array}{cc}1& -26\\0&
27\end{array}\right][/tex]

[tex]f(a)=3\cdot a^3-2\cdot a+4\cdot e=3\cdot\left[\begin{array}{cc}1& -26\\0& 27\end{array}\right] -2\cdot\left[\begin{array}{cc}1& -8\\0& 9\end{array}\right]+4\cod\left[\begin{array}{cc}1& 0\\0& 1\end{array}\right]=\\\\
=\left[\begin{array}{cc}3\cdot1-2\cdot1+4\cdot1& 3\cdot(-26)-2\cdot(-8)+4\cdot0\\3\cdot0-2\cdot0+4\cdot0& 3\cdot27-2\cdot9+4\cdot1\end{array}\right]=\left[\begin{array}{cc}5& -62\\0& 67\end{array}\right][/tex]

х-v автобуса

х-15 - v теплохода

(х-15)*8.5=6х+40

8.5х-127.5=6х+40

2.5х=167.5

х=67 (км/ч)