3.2 Матрицы \( 3^{*} 3 \) 1. \( \left(\begin{array}{ccc}12 & 5 & 6 \\ -13 & 2 & 5 \\ 1 & 8 & -9\end{array}\right) \cdot X \cdot\left(\begin{array}{ccc}0 & 3 & 10 \\ -9 & -6 & -11 \\ 12 & 1 & 10\end{array}\right)=\left(\begin{array}{ccc}-1314 & 267 & -428 \\ 2472 & 89 & 718 \\ -1716 & 409 & 522\end{array}\right) \)

Rafael ordered some books online and spent a total of \( \$ 89 \). Each book cost \( \$ 5 \) and he paid a total of \( \$ 4 \) for shipping. How many books did he buy? (a) Write an equation that could be used to answer the question above. First, choose the appropriate form. Then, fill in the blanks with the numbers 89,5 , and 4 . Let \( b \) represent the number of books. \( \square b-\square=\square=\square \) \( b=\square \)

г) \( \log _{\frac{1}{5}}^{2}\left(x^{2}+2 x+1\right)-31 \log _{\frac{1}{5}} \frac{x+1}{5}+15<0 \)

\( y = f ( x ) = \frac { 1 x - 4 } { 2 x - 6 } \)

2) \( (-x)(-y) \)

Question 24 Which of the following expressions is equivalent to \( \frac{\sqrt{12}+\sqrt{6}}{\sqrt{3}} \) ? a. \( \frac{6+\sqrt{15}}{3} \) b. \( \frac{2+\sqrt{2}}{3} \) c. \( 2+\sqrt{2} \)