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Matriks
Kelas X

[tex] \left(\begin{array}{cc}2 & 1 \\ 1 & -3 \end{array}\right) \left(\begin{array}{cc}2 -x \\ 3x + 2y \end{array}\right) = \left(\begin{array}{cc} 13 \\ -4 \end{array}\right) \\
\left(\begin{array}{cc} 4 - 2x + 3x + 2y \\ 2 - x - 9x - 6y \end{array}\right) = \left(\begin{array}{cc} 13 \\ -4 \end{array}\right) \\
\left(\begin{array}{cc} x + 2y + 4 \\ -10x - 6y + 2 \end{array}\right) = \left(\begin{array}{cc} 13 \\ -4 \end{array}\right) [/tex]

x + 2y + 4 = 13
x + 2y = 9 |x 3|
3x + 6y = 27 ... (i)

-10x - 6y + 2 = -4
10x + 6y = 6 ... (ii)

Eliminasi (i) dan (ii)

3x + 6y = 27
10x + 6y = 6
––––––––– (–)
-7x = 21
x = -3

3(-3) + 6y = 27
6y = 27 + 9
6y = 36
y = 6

5y - 2x = 5(6) - 2(-3)
= 30 + 6 = 36

5y - 2x = 5(6) - 2(-3) = 36