document.write( "Question 561290: I need to solve by addition: 5x-4y=9 and -x+2y=3. I know I need to multiply the first two coefficients by 5, but they both come up as -5. Is there any solution or is there no solution because it is dependent? \n" ); document.write( "

Algebra.Com's Answer #364232 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
(1) $\"+5x+-+4y+=+9+\"$
\n" ); document.write( "(2) $\"+-x+%2B+2y+=+3+\"$
\n" ); document.write( "Just leave (1) alone and multiply both sides of (2)
\n" ); document.write( "by $\"+2+\"$
\n" ); document.write( "If you do the same thing to both sides, the equation is still true
\n" ); document.write( "(2) $\"+-2x+%2B+4y+=+6+\"$ is the result
\n" ); document.write( "Now just add the equations
\n" ); document.write( "(1) $\"+5x+-+4y+=+9+\"$
\n" ); document.write( "(2) $\"+-2x+%2B+4y+=+6+\"$
\n" ); document.write( " $\"+3x+=+15+\"$
\n" ); document.write( " $\"+x+=+5+\"$
\n" ); document.write( "Plug this value back into (2)
\n" ); document.write( "(2) $\"+-5+%2B+2y+=+3+\"$
\n" ); document.write( "(2) $\"+2y+=+3+%2B+5+\"$
\n" ); document.write( "(2) $\"+2y+=+8+\"$
\n" ); document.write( "(2) $\"+y+=+4+\"$
\n" ); document.write( "The solution is (5,4) \n" ); document.write( "

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