Question 237895
Write the augmented matrix for the system of equations and solve the system using Gauss-Jordan Elimination.
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10x+8y+20Z=6,000
10x+20y+40Z=11,000
100X+20y+200z=36,900 
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Subtract 1st from 2nd and Subtract 10 times 1st from 3rd to get:
10x+8y+20Z=6,000
 0x+12y+20z = 5000
 0x-60y+0z = -23100
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Solve the 3rd equation for "y"
y = 385
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Substitute into the 2nd and solve for "z"
12*385 + 20z = 5000
z = 19
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Substitute into the 1st and solve for "x"
10x + 8*385 + 20*19 = 6000
x = 254
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Cheers,
Stan H.