2) \( \left(2 x^{\prime}+23\right)(8 x+2) \) and \( (20 x-\$ 2) \) ate throe conseculive terms of an arithmetic sequence. Prove that the compmon differcice or the sequence is 12

Diketahui sistem persamaan tinier berikut ini : \[ \begin{array}{l}-1 x+y+2 z=2 \\ 3 x-1 y+z=6 \\ -1 x+3 y+4 z=4\end{array} \] Tentukan solusi persamaan linear tersebut menggunakan metode gauss!

1) \( \frac{10 x+8}{3 a-b}-\frac{9 x+5}{3 a-b}= \)

In the \( x y \)-plane, a parabola has vertex \( (9,-14) \) and intersects the \( x \)-axis at two points. If the equation of the parabola is written in the form \( y=a x^{2}+b x+c \) where \( a, b \), and \( c \) are constants, which of the following could be the value of \( a+b+c \) ? (A) -23 (B) -19 (D) -12

Roger was told to think of a number, add 20 , then divide the result by 3 . The answer was Jower than Roger's original number. Deteruine the range of possible numbers Roger may have originally chosen.

Subtract the polynomials: \( (5x^{3} + 2x^{2} - 7) - (3x^{3} - x^{2} + 4) \)