document.write( "Question 1175220: Find the solution to the system of equations:\r
\n" ); document.write( "\n" ); document.write( "(x - 2y + z = -3
\n" ); document.write( "|y + 2z = -5
\n" ); document.write( "|x + y + 3z = -6
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Algebra.Com's Answer #800795 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "There are many methods -- elimination, Cramer's rule, matrices with Gauss-Jordan....

\n" ); document.write( "Using Cramer's rule is a well-defined process; if you want to solve the problem that way, just do it.

\n" ); document.write( "Using Gauss-Jordan elimination is also a well-defined process, but there are multiple possible paths to the solution, and the process is prone to simple arithmetic errors.

\n" ); document.write( "Given no instruction on what method to use, I would solve the problem algebraically using elimination.

\n" ); document.write( "Since one of the equations involves only two of the three variables, I would solve that equation for one variable in terms of the other and then use substitution to reduce the problem to two equations in two unknowns.

\n" ); document.write( "Presumably if you are working on a problem like this you know how to solve a system of two linear equations; so I leave the last part of the work to you.

\n" ); document.write( "\"y%2B2z+=+-5\"
\n" ); document.write( "\"y+=+-5-2z\"

\n" ); document.write( "Then

\n" ); document.write( "\"x-2%28-5-2z%29%2Bz+=+-3\"
\n" ); document.write( "\"x%2B5z+=+-13\" [1]

\n" ); document.write( "and

\n" ); document.write( "\"x%2B%28-5-2z%29%2B3z+=+-6\"
\n" ); document.write( "\"x%2Bz+=+-1\" [2]

\n" ); document.write( "Solve [1] and [2] for x and z; then find y from one of the given equations.

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