document.write( "Question 54421: Solve the system by substitution:\r
\n" ); document.write( "\n" ); document.write( "x-2y=6
\n" ); document.write( "y=2x-6 \n" ); document.write( "
Algebra.Com's Answer #36746 by funmath(2933)\"\" \"About 
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L1) x-2y=6
\n" ); document.write( "L2) y=2x-6
\n" ); document.write( "-----------Since L2 is already solved for y, plug (2x-6) in for y in L1 and solve for x:
\n" ); document.write( "x-2(2x-6)=6
\n" ); document.write( "x-4x+12=6
\n" ); document.write( "-3x+12=6
\n" ); document.write( "-3x+12-12=6-12
\n" ); document.write( "-3x=-6
\n" ); document.write( "-3x/-3=-6/-3
\n" ); document.write( "x=2
\n" ); document.write( "------------Plug (2) in for x in L2 and solve for y:
\n" ); document.write( "y=2(2)-6
\n" ); document.write( "y=4-6
\n" ); document.write( "y=-2
\n" ); document.write( "------------The solution (x,y)=(2,-2)
\n" ); document.write( "Check in both equations by substituting (x,y)=(2,-2) and see if it equals out:
\n" ); document.write( "L1) (2)-2(-2)=6
\n" ); document.write( "2+4=6
\n" ); document.write( "6=6 L1 checks out.
\n" ); document.write( "L2) (-2)=2(2)-6
\n" ); document.write( "-2=4-6
\n" ); document.write( "-2=-2 L2 checks out also, so we can say with confidence that the solution indeed is:(x,y)=(2,-2)
\n" ); document.write( "Happy Calculating!!!
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