jika x = 4, 2x - y = 5 3x - 4y - 3z = 3 maka berapakah nilai 2z?

x = 4 ... (1)
2x - y = 5 ... (2)
3x - 4y - 3z = 3 ... (3)

Substitusi (1) ke (2)
2(4) - y = 5
8 - y = 5
y = 3

Substitusi (1) dan y = 3 ke (3)
3(4) - 4(3) - 3z = 3
12 - 12 - 3z = 3
-3z = 3
z = -1

Nilai 2z
= 2(-1)
= -2

x = 4
maka 2x - y = 5
2(4) - y = 5
8 - y = 5
y = 3

3x - 4y - 3z = 3
3 (4) - 4( 3) - 3z  = 3
12-12- 3z = 3
-3z = 3
z = -1