2x+3y-z=10 x+y+z=5 4x+5y+z=20 Bantu please!

4X+5Y=20-Z (x1) 4X+5Y=20-Z
X+Y=5-Z (x4) 4X+4Y=20-Z
__________—
Y=0

2X+3(0)-Z=10 => 2X-Z=10
X+0+Z=5 => X+Z=5
4X+5(0)+Z=20 => 4X+Z=20

2X-Z=10
2X=10+Z
X=10+Z/2

X+Z=5
(10+Z/2)+Z=5
10+Z+2Z/2=5
10+3Z/2=5
10+3Z=10
3Z=10-10
3Z=0

Y=0 , Z=0 , maka:

X+Y+Z=5
X=5

Substitusi untuk pembuktian:

2X+3Y-Z=10
2(5)+3(0)-0=10

4X+5Y+Z=20
4(5)+5(0)+020

Jadi , X=5 , Y=0 , Z=0