SOLUTION: x+2y-3z=2 3x-z=-8 2x-3y+5z=-9 by elimination

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Question 860688: x+2y-3z=2
3x-z=-8
2x-3y+5z=-9
by elimination
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x%2B2y-3z=2
2.3x-z=-8
3.2x-3y%2B5z=-9
from Eq. 2,
z=3x%2B8
Substitute into eqs. 1 and 3,
x%2B2y-3%283x%2B8%29=2
x%2B2y-3x-12=2
-2x%2B2y=14
4.-x%2By=7
.
.
2x-3y%2B5%283x%2B8%29=-9
2x-3y%2B15x%2B40=-9
5.17x-3y=-49
Multiply eq. 4 by 3 and add to eq. 5,
-3x%2B3y%2B17x-3y=21-49
14x=-28
x=-2
Now work backwards,
From eq. 4,
-%28-2%29%2By=7
2%2By=7
y=5
and finally,
z=3%28-2%29%2B8
z=2