document.write( "Question 1203611: x+4y-6z=-1
\n" ); document.write( "2x-y+2z=-7
\n" ); document.write( "-x+2y-4z=5 \n" ); document.write( "

Algebra.Com's Answer #839299 by MathLover1(20850) $\"\"$ $\"About$

You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( " $\"x%2B4y-6z=-1\"$ .....eq.1
\n" ); document.write( " $\"2x-y%2B2z=-7\"$ .......eq.2
\n" ); document.write( " $\"-x%2B2y-4z=5\"$ .......eq.3
\n" ); document.write( "-----------------------------------------\r
\n" ); document.write( "\n" ); document.write( "start with\r
\n" ); document.write( "\n" ); document.write( " $\"x%2B4y-6z=-1\"$ .....eq.1
\n" ); document.write( " $\"-x%2B2y-4z=5\"$ .......eq.3
\n" ); document.write( "----------------------------------------add both\r
\n" ); document.write( "\n" ); document.write( " $\"x%2B4y-6z-x%2B2y-4z=-1%2B5\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"6y-10z=4\"$ ...both sides divide by $\"2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"3y-5z=2\"$ ....solve for $\"y\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=%285z%2B2%29%2F3\"$ .....eq.1a\r
\n" ); document.write( "\n" ); document.write( "go to\r
\n" ); document.write( "\n" ); document.write( " $\"x%2B4y-6z=-1\"$ .....eq.1......multiply by $\"2\"$
\n" ); document.write( " $\"2x-y%2B2z=-7\"$ .......eq.2
\n" ); document.write( "-------------------------------------
\n" ); document.write( " $\"2x%2B8y-12z=-2\"$ .....eq.1
\n" ); document.write( " $\"2x-y%2B2z=-7\"$ .......eq.2
\n" ); document.write( "-------------------------------------subtract\r
\n" ); document.write( "\n" ); document.write( " $\"2x%2B8y-12z-%282x-y%2B2z%29=-2-%28-7%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"2x%2B8y-12z-2x%2By-2z=-2%2B7\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"9y-14z=5\"$ ....solve for $\"y\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=%2814z%2B5%29%2F9\"$ .....eq.1b\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "from eq.1a and eq.1b we have\r
\n" ); document.write( "\n" ); document.write( " $\"%285z%2B2%29%2F3=%2814z%2B5%29%2F9\"$ ....cross multiply\r
\n" ); document.write( "\n" ); document.write( " $\"9%285z%2B2%29=3%2814z%2B5%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"45z%2B18=42z%2B15\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"45z-42z=15-18\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"3z=-3\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"z=-1\"$ \r
\n" ); document.write( "\n" ); document.write( "go to\r
\n" ); document.write( "\n" ); document.write( " $\"y=%285z%2B2%29%2F3\"$ .....eq.1a, substitute $\"z=-1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=%285%28-1%29%2B2%29%2F3\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=%28-5%2B2%29%2F3\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=-3%2F3\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=-1\"$ \r
\n" ); document.write( "\n" ); document.write( "go to\r
\n" ); document.write( "\n" ); document.write( " $\"x%2B4y-6z=-1\"$ .....eq.1, substitute $\"y=-1\"$ and $\"z=-1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x%2B4%28-1%29-6%28-1%29=-1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x-4%2B6=-1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x%2B2=-1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x=-1-2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x=-3\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "solutions:\r
\n" ); document.write( "\n" ); document.write( " $\"x=-3\"$
\n" ); document.write( " $\"y=-1\"$
\n" ); document.write( " $\"z=-1\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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