Question

Tolong bantu jawab no 2 pake cara

Answer 1

2x-2y-2z=9 | x1
x-6y-3z=-28 | x2
--------------------------
2x-2y-2z=9
2x-12y-6z=-56
---------------------- (-)
10y+4z=65

2x-2y-2z=9 | x3
3x+2y+z=16 | x2
-------------------------
6x-6y-6z=27
6x+4y+2z=32
---------------------- (-)
-10y-8z=-5
10y+8z=5

10y+4z=65
10y+8z=5
--------------- (-)
-4z=60
z=-15

10y+4z=65
10y+4(-15)=65
10y-60=65
10y=125
y=12,5

2x-2y-2z=9
2x-2(12,5)-2(-15)=9
2x-25+30=9
2x+5=9
2x=4
x=2

jadi x=2, y=12,5, z=-15