document.write( "Question 23690: Please help me solve the following equations\r
\n" ); document.write( "\n" ); document.write( "X+3y=4\r
\n" ); document.write( "\n" ); document.write( "2x-y=8 \n" ); document.write( "
Algebra.Com's Answer #12471 by longjonsilver(2297)\"\" \"About 
You can put this solution on YOUR website!
Look at my Lessons on Simultaneous equation, on this website... they help.\r
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\n" ); document.write( "\n" ); document.write( "solution is:
\n" ); document.write( "x+3y=4 --eqn1
\n" ); document.write( "2x-y=8 --eqn2\r
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\n" ); document.write( "\n" ); document.write( "scale up eqn1 by factor 2, giving:
\n" ); document.write( "2x+6y=8 --eqn1
\n" ); document.write( "2x-y=8 --eqn2\r
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\n" ); document.write( "\n" ); document.write( "Now, the x-terms are the same digit...both a 2. Looking at the signs of these, they are the SSSSSSSSSame (both +), so we SSSSSSSSubtract the equations, to give:\r
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\n" ); document.write( "\n" ); document.write( "5y = 0
\n" ); document.write( "so y = 0.\r
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\n" ); document.write( "\n" ); document.write( "Hence, x+3y=4 becomes
\n" ); document.write( "x+3(0) = 4
\n" ); document.write( "x = 4\r
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\n" ); document.write( "\n" ); document.write( "and CHECK in the other equation:
\n" ); document.write( "2x-y=8 becomes
\n" ); document.write( "2(4)-0 = 8
\n" ); document.write( "8=8 --> which is correct\r
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\n" ); document.write( "\n" ); document.write( "jon.
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