Tentukan HP dari: A. x+y+4z=15 B. x-y+z=2 C. x+2y-3z=-4

x+y+4z=15
x-y+ z  =2
--------------   +
 2x+5z=17

x+y+4z=15.............×2
x+2y-3z=-4.............×1
------------------------------  -
maka,
2x+2y+8z=30
x+2y-3z=-4
------------------    -
x+11z=34.........×2
2x+5z=17.........×1
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maka,
2x+22z=68
2x+5z=17
---------------  -
17z=51
z=3
2x+5z=17
2x+5(3)=17
2x=2
x=1
x-y+z=2
1-y+3=2
y=2
hp={x=1; y=2; z=3}