document.write( "Question 897529: Hello. I hope I put this question in the correct topic. I am norwegian, and I don't know the English equivalent of my question. Anyway, here goes:\r
\n" ); document.write( "\n" ); document.write( "x+2y+3z=14 I
\n" ); document.write( "4x-y-z=-1 II
\n" ); document.write( "7x+5y+z=20 III\r
\n" ); document.write( "\n" ); document.write( "What is x, y and z? (If you can show it from where I last learned, and figured out, that would be great):
\n" ); document.write( "x = 14-2y-3z
\n" ); document.write( "-> 4(14-2y-3z)-y-z=-1
\n" ); document.write( "-> 7(14-2y-3z)+5y+z=20\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "PS: I got
\n" ); document.write( "-9y-13z=-57
\n" ); document.write( "-9y-20z=-78 What then? (...if correct up to here)\r
\n" ); document.write( "\n" ); document.write( "Thank you so much in advance!! :) \n" ); document.write( "
Algebra.Com's Answer #544183 by MathTherapy(10552)\"\" \"About 
You can put this solution on YOUR website!
Hello. I hope I put this question in the correct topic. I am norwegian, and I don't know the English equivalent of my question. Anyway, here goes:\r
\n" ); document.write( "\n" ); document.write( "x+2y+3z=14 I
\n" ); document.write( "4x-y-z=-1 II
\n" ); document.write( "7x+5y+z=20 III\r
\n" ); document.write( "\n" ); document.write( "What is x, y and z? (If you can show it from where I last learned, and figured out, that would be great):
\n" ); document.write( "x = 14-2y-3z
\n" ); document.write( "-> 4(14-2y-3z)-y-z=-1
\n" ); document.write( "-> 7(14-2y-3z)+5y+z=20\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "PS: I got
\n" ); document.write( "-9y-13z=-57
\n" ); document.write( "-9y-20z=-78 What then? (...if correct up to here)\r
\n" ); document.write( "\n" ); document.write( "Thank you so much in advance!! :)
\n" ); document.write( "

\n" );
document.write( " x + 2y + 3z =  14 ------- eq (i)      
\n" );
document.write( "4x -  y -  z = - 1 ------- eq (ii)
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document.write( "7x + 5y +  z =  20 ------- eq (iii)\r
\n" );
document.write( "\n" );
document.write( "PS: I got
\n" );
document.write( "-9y-13z=-57
\n" );
document.write( "-9y-20z=-78         What then? (...if correct up to here)\r
\n" );
document.write( "\n" );
document.write( "Yes, you are CORRECT up to here. Good job!!\r
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document.write( "\n" );
document.write( "- 9y - 13z = - 57 -------- eq (iv)
\n" );
document.write( "- 9y - 20z = - 78 -------- eq (v)
\n" );
document.write( "        7z =   21 -------- Subtracting eq (v) from eq (iv)
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document.write( "z = \"21%2F7\", or \"z+=+3\"
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document.write( "**Notice that when eq (v) was subtracted from eq (iv), the y variable was ELIMINATED\r
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document.write( "\n" );
document.write( "Next, you substitute 3 for z in either eq (iv) or eq (v)
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document.write( "- 9y - 13(3) = - 57 -------- Substituting 3 for z in eq (iv)
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document.write( "- 9y -    39 = - 57
\n" );
document.write( "- 9y         = - 57 + 39
\n" );
document.write( "- 9y         = - 18
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document.write( "y = \"%28-+18%29%2F%28-+9%29\", or \"y+=+2\"\r
\n" );
document.write( "\n" );
document.write( "x + 2(2) + 3(3) = 14 ------- Substituting 3 for z, and 2 for y in eq (i)
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document.write( "x + 4 + 9 = 14
\n" );
document.write( "x + 13 = 14
\n" );
document.write( "x = 14 - 13
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document.write( "\"x++=+1\"
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document.write( "Solution: \"highlight_green%28highlight_green%28system%28x+=+1%2C+y+=+2%2C+z+=+3%29%29%29\"
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document.write( "You can do the check!! \r
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document.write( "\n" );
document.write( "Send comments, “thank-yous,” and inquiries to “D” at MathMadEzy@aol.com.
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document.write( "Further help is available, online or in-person, for a fee, obviously. \r
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