Factor by grouping (sometimes called the ac-method). \[ 2 x^{2}+7 x-9 \] First, choose a form with appropriate signs. Then, fill in the blanks with numbers to be used for grouping. Finally, show the factorization.

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 !

a. \( \quad(6 x-18)(3 x+2)=0 \)

4. \( \log _{4} x^{2}-2 \log _{4} x-3=0 \)

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

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