hitunglah nilai* x dan y apabila 8x =4 + 4y dan 2x + 3y -21=0 buat lah dgn cara determinan mohon dibantu ya kk/abg

SPLDV

8x = 4 + 4y
8x - 4y = 4 [÷ 4]
2x - y = 1 ... (i)

2x + 3y - 21 = 0
2x + 3y = 21 ... (ii)

Bentuk Matriks yang sesuai :
[tex] \left(\begin{array}{cc} 2 & -1 \\ 2 & 3 \end{array}\right) \left(\begin{array}{cc} x \\ y \end{array}\right) = \left(\begin{array}{cc} 1 \\ 21 \end{array}\right) \\
\\
D = \left|\begin{array}{cc} 2 & -1 \\ 2 & 3 \end{array}\right| = 6 + 2 = 8 \\
\\
Dx = \left|\begin{array}{cc} 1 & -1 \\ 21 & 3 \end{array}\right| = 3 + 21 = 24 \\
\\
Dy = \left|\begin{array}{cc} 2 & 1 \\ 2 & 21 \end{array}\right|= 42 - 2 = 40 \\
\\
x = \frac{Dx}{D} = \frac{24}{8} = 3 \\
y = \frac{Dy}{D} = \frac{40}{8} = 5 [/tex]

HP : {3 , 5}