tolongin donk penting pakai cara ya kak

Misal :
Permen = x
Kerupuk = y
Roti = z

D1:
Tini : x+2y+z = 4000 (Pers1)
Tono : 2x+y+z = 6500 (Pers2)
Tina : 3x+3y+2z = 7500 (Pers3)
D2: x,y,z ?
D3:
Eliminasi Pers1 & 2
x+2y+z=4000 |x2|
2x+y+z=6500 |x1 |

2x+4y+2z=8000
2x+y+z=6500
_____________-
3y+z=1500 (Pers4)

Eliminasi Pers2 & 3
2x+y+z=6500 |x3|
3x+3y+2z=7500 |x2|

6x+3y+3z=19500
6x+6y+4z=15000
______________-
-3y-z=4500 (Pers5)

Eliminasi Pers4 & 5
3y+z=1500
-3y-z=4500
__________+
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