Holly was matched with several people on a dating app. She went on one dinner date, five coffee dates, and two movie dates. Suppose the variables \( x, y \), and \( z \) represent the cost of a dinner date, a coffe date, and a movie date respectively. Use these variables to represent the total amount Holly spent on her dating experiences, if she paid.

\( 6 a ^ { 2 } + 3 a c + 4 a b + 2 b \)

Diketahui matriks \( M=\left[\begin{array}{ccc}3 & 0 & -2 \\ -5 & 2 & 0 \\ 0 & -3 & 4\end{array}\right] \) dan \( N=\left[\begin{array}{ccc}0 & 7 & 5 \\ 5 & -3 & 2 \\ 0 & -4 & -3\end{array}\right] \) adalah matriks berordc 3x3. Jika \( \mathrm{M}+\mathrm{N} \), maka tentukanlah hasil dari penjumlahan kedua matriks tersebut !

7 Realizar el siguiente sistema de ecuaciones por Método de eliminación (suma ylo Resta) \( \begin{array}{l}4 x+2 y=-2 \\ 3 x+5 y=9\end{array} \)

3Ldentifica y realiza los siguentes productos notables de polinomios: \( \begin{array}{ll}\text { A) }(2 a b+7 c)(2 a b-7 c)=\quad & \text { b) }(5 a-2 b)^{2}=\end{array} \)

\( 3 a ^ { 2 } + 3 a c + 4 a b + 2 b c \)