SOLUTION: {{please help}}how can i solve this..{{{2x-4y=12 3x+5z=3 4y-2z=7}}}

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Question 576372: {{please help}}how can i solve this..2x-4y=12+3x%2B5z=3+4y-2z=7
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
2x - 4y + 0z =12
3x + 0y + 5z = 3
0x + 4y - 2z = 7
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Add eqn 1 & 3
2x - 2z = 19 eqn A
3x + 5z = 3 eqn 2
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Multiply eqn A by 3 and eqn 2 by 2
6x - 6z = 57 eqn A * 3
6x +10z = 6 eqn 2 * 2
---------------------- Subtract
-16z = 51
z = -51/16
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Sub for z in eqn 2, find x
Sub for a in eqn 3, find y
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That's one way. I prefer determinants, tho.