5x + y + z = 72.000 3x + 2y + z= 90.000 x + 2y + 3z = 65.000 berapa nilai x y z...???

3x + 2y + z= 90.000
5x + y + z = 72.000
--------------------------- (-)
-2x + y = 18.000

5x + y + z = 72.000    (x3)  -> 15x + 3y + 3z = 216.000
x + 2y + 3z = 65.000  (x1)  ->     x + 2y + 3z =   65.000
                                               --------------------------------- (-)
                                               14x + y = 151.000
                                                -2x + y =  18.000
                                               ------------------------- (-)
                                                16x = 133.000
                                                    x = 8.312,5

-2(8.312,5) + y = 18000
-16.625 + y = 18.000
y = 34.625

5x + y + z = 72.000
5(8.312,5) + 34.625 + z = 72.000
41.562,5 + 34.625 + z = 72.000
z = -4.187,5

Maaf jika salah karna saya merasa angka hasilnya sedikit aneh sebab desimal dan negatif seperti itu :)