Question

X-2y+2z=15
2x-y-3z=-8
3x+2y-z=2
nilai x+y+z adalah

Answer 1

X-2y+2z=15 
2x-y-3z=-8   | kali 2
3x+2y-z=2

X-2y+2z=15 
4x-2y-6z=-16
3x+2y-z=2

X-2y+2z=15 
4x-2y-6z=-16
-------------------- -
-3x+8z=31

4x-2y-6z=-16
3x+2y-z=2
-------------------- +
7x-7z=-14

-3x+8z=31| kali 7
7x-7z=-14 | kali 3

-21x+56z=217
21x-21z=-42
---------------------- +
35z= 175
z=5

-3x+8(5)=31
-3x+40=31
-3x=-9
x=3

3-2y+2(5)=15
3-2y+10=15
13-2y=15
-2y=-2
y=1
x+y+z=3+1+5=9
jadi, hasil dari x+y+z=9.