Question 1047631
Solve the following system of equations:
2x+3y-x=0
X-2y-4z=14
3x+y-8z=17 
Interchange row 1 and row 2 to get:
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X-2y-4z=14
2x+3y-x=0
3x+y-8z=17 
Subtract 2*row 1 from row 2
Subtract 3*row 1 from row 3
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x - 2y - 4z = 14
0 + 7y +7z = -28
0 + 7y -5z =  17
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Subtract row 2 from row 3 to get:
x - 2y - 4z = 14
0 + 7y + 7z = -28
0 + 0  -12z =  45
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Solve row 3 for "z"
z = -15/4
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Divide thru row 2 by 7 to get::
x - 2y - 4z = 14
0 + y  +  z = -4
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Substitute for "z" and solve for "y"::
x - 2y - 4z = 14
y = -4+15/4
y = -1/4
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Substitute for y and z in row 1 and solve for "x":
x - 2(-1/4) - 4(-15/4) = 14
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x + (1/2) + 15 = 14
x = -3/2
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Cheers,
Stan H.
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