<PRE><B>Question 146084</B>
Please solve the system of equation for all variables using a matrix.
-2x+y = -4
x +3y = 9
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My solution 
2 1=-4
1 3=9 
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r2 reverse r1
1 3=9
2 1=-4
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r2* -2
1 3=9
0 -1=-6
Comment: You cannot subtract 2 from the x-term, 2 from the y-,and 2 from 
the constant and still maintain the equation.
What should you do?
You should subtract 2*(1st row) from the 2nd row to get
0 -5 = -22
Then continue on.
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Cheers,
Stan H.
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r2* 2 
1 3=9
0 1=-12 
r2*-3+r1
1 0=-6
0 1=-12
x= -6 and y= -12 
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