document.write( "Question 319680: The sum of three numbers is 3. The first, minus the second, plus three times the third, is -7. The third plus 3 times the first, plus the second is 11. What are the numbers? \n" ); document.write( "

Algebra.Com's Answer #228965 by mananth(16946) $\"\"$ $\"About$

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let the numbers be x , y , z.
\n" ); document.write( "x+y+z=3
\n" ); document.write( "z= 3-(x+y)
\n" ); document.write( "..
\n" ); document.write( "x+y-3z=-7
\n" ); document.write( "z+3x+y=11
\n" ); document.write( "..
\n" ); document.write( "plug the value of z in both the equations
\n" ); document.write( "x+y-3(3-(x+y)=-7
\n" ); document.write( "x+y-3(3-x-y)=-7
\n" ); document.write( "x+y-9+3x+3y=-7
\n" ); document.write( "4x+4y=2
\n" ); document.write( "2x+2y=1
\n" ); document.write( "..
\n" ); document.write( "z+3x+y=11
\n" ); document.write( "3-x-y+3x+y=11
\n" ); document.write( "2x=8
\n" ); document.write( "x=4
\n" ); document.write( "..
\n" ); document.write( "2x+2y=1
\n" ); document.write( "8+2y=1
\n" ); document.write( "2y=-7
\n" ); document.write( "y=-7/2
\n" ); document.write( "..
\n" ); document.write( "z=3-x-y
\n" ); document.write( "z=3-4+7/2
\n" ); document.write( "6-8+7 /2
\n" ); document.write( "=5/2
\n" ); document.write( "z=5/2 \n" ); document.write( "

\n" );