tolong guru saya killer

jawab
x = bukutulis
y = pena

5x  + y = 30.000
8x+2y = 40.000 --> sederhanakandi bagi 2
4x+y = 20.000
dalam mtriks

[5...1][x] = [30.000]
[4...1][y]....[20.000]

jawab  (B)