Question

2x+2y+z=70.000
x+2y+2z=90.000
2x+2y+3z=130.000

cari x,y,z dengan caranya ya

Answer 1

2x + 2y + z = 70.000
x + 2y + 2z = 90.000
_________________ -
x - z = -20.000

x + 2y + 2z = 90.000
2x + 2y + 3z = 130.000
____________________ -
-x - z = -40.000
x + z = 40.000

eliminasi:
x - z = -20.000
x + z = 40.000
____________ +
2x = 20.000
x = 10.000
z = 30.000
dan y ⇒ 10.000 + 2y + 60.000 = 90.000
2y = 20.000
y = 10.000
maka (x,y,z) = (10.000, 10.000, 30.000)

Answer 2

Eliminasi pers 1 dan 3
2x+2y+z=70.000
2x+2y+3z=130.000
-2z=-60000
z=30000
substitusi pers 2
x+2y+2.30000=90000
x+2y=30000 -----> x 2
2x+4y=60000
substitusi pers 3
2x+2y+3.30000=130000
2x+2y=40000
eliminasi keduanya
2y=20000
y=10000
2x+2.10000=40000
2x=20000
x=10000
(x,y,z)=(10000,10000,30000)