document.write( "Question 208209: SYSTEM OF 3 EQUATIONS WITH 3 UNKNOWNS
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\n" ); document.write( "FIND SOLUTION SET FOR THE FOLLOWING SYSTEM OF EQUATIONS:\r
\n" ); document.write( "\n" ); document.write( " X -Y +5Z = 2
\n" ); document.write( " 4X -3Y +5Z = 3
\n" ); document.write( " 3X -2Y +4Z = 1
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Algebra.Com's Answer #157516 by pjalgeb(9)\"\" \"About 
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\n" ); document.write( "SOLUTION:\r
\n" ); document.write( "\n" ); document.write( "The augmented 3x3 matrix for the above system of equations is:\r
\n" ); document.write( "\n" ); document.write( " | 1 -1 5 | 2 |
\n" ); document.write( " | 4 -3 5 | 3 |
\n" ); document.write( " | 3 -2 4 | 1 |\r
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\n" ); document.write( "\n" ); document.write( "By Cramers Rule: \r
\n" ); document.write( "\n" ); document.write( "\"x+=+Dx%2FD\"
\n" ); document.write( "\"y+=+Dy%2FD\"
\n" ); document.write( "\"z+=+Dz%2FD\"\r
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\n" ); document.write( "\n" ); document.write( "First, lets solve for D, Dx, Dy and Dz:\r
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\n" ); document.write( "\n" ); document.write( "D = | 1 -1 5 |
\n" ); document.write( " | 4 -3 5 |
\n" ); document.write( " | 3 -2 4 | \r
\n" ); document.write( "\n" ); document.write( "D = 1(-12+10) - 4(-4+10) + 3(-5+15)
\n" ); document.write( "D = 1(-2) -4(6) + 3(10)
\n" ); document.write( "D = -2 -24 +30
\n" ); document.write( "D = -26 +30\r
\n" ); document.write( "\n" ); document.write( "\"D+=+4\"\r
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\n" ); document.write( "\n" ); document.write( "Dx = | 2 -1 5 |
\n" ); document.write( " | 3 -3 5 |
\n" ); document.write( " | 1 -2 4 |\r
\n" ); document.write( "\n" ); document.write( "Dx = 2(-12+10) - 3(-4+10) +1(-5+15)
\n" ); document.write( "Dx = 2(-2) - 3(6) + 1(10)
\n" ); document.write( "Dx = -4 - 18 + 10
\n" ); document.write( "Dx = -22 +10\r
\n" ); document.write( "\n" ); document.write( "\"Dx+=+-12\"\r
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\n" ); document.write( "\n" ); document.write( "Dy = | 1 2 5 |
\n" ); document.write( " | 4 3 5 |
\n" ); document.write( " | 3 1 4 | \r
\n" ); document.write( "\n" ); document.write( "Dy = 1(12-5) -4(8-5) +3(10-15)
\n" ); document.write( "Dy = 1(7) -4(3) +3(-5)
\n" ); document.write( "Dy = 7 -12 -15
\n" ); document.write( "Dy = -5 -15\r
\n" ); document.write( "\n" ); document.write( "\"Dy+=+-20\"\r
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\n" ); document.write( "\n" ); document.write( "Dz = | 1 -1 2 |
\n" ); document.write( " | 4 -3 3 |
\n" ); document.write( " | 3 -2 1 |\r
\n" ); document.write( "\n" ); document.write( "Dz = 1(-3+6)- 4(-1+4)+ 3(-3+6)
\n" ); document.write( "Dz = 1(3) - 4(3) + 3(3)
\n" ); document.write( "Dz = 3 -12 + 9
\n" ); document.write( "Dz = -9 + 9\r
\n" ); document.write( "\n" ); document.write( "\"Dz+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+Dx%2FD+=+-12%2F4\"
\n" ); document.write( "\"x+=+-3\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=+Dy%2FD+=+-20%2F4\"
\n" ); document.write( "\"y+=+-5\"\r
\n" ); document.write( "\n" ); document.write( "\"z+=+Dz%2FD+=+0%2F4\"
\n" ); document.write( "\"z+=+0\"\r
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\n" ); document.write( "\n" ); document.write( "Answer: The solution set is {(-3,-5, 0)}\r
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