document.write( "Question 56682: Solve the system by substitution.
\n" ); document.write( "x+y=12
\n" ); document.write( "y=2x \n" ); document.write( "
Algebra.Com's Answer #38456 by funmath(2933)\"\" \"About 
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Solve the system by substitution.
\n" ); document.write( "L1) x+y=12
\n" ); document.write( "L2) y=2x
\n" ); document.write( ":
\n" ); document.write( "Substitute 2x in for y in L1) and solve for y:
\n" ); document.write( "x+(2x)=12
\n" ); document.write( "3x=12
\n" ); document.write( "3x/3=12/3
\n" ); document.write( "x=4
\n" ); document.write( ":
\n" ); document.write( "Substitute 4 in for x in L2) and solve for x:
\n" ); document.write( "y=2(4)
\n" ); document.write( "y=8
\n" ); document.write( "The solution is (x,y)=(4,8)
\n" ); document.write( ":
\n" ); document.write( "Check by substituting (4,8) into L1 and L2 and see if they equal.
\n" ); document.write( "L1) (4)+(8)=12
\n" ); document.write( "12=12 L1 checks out!
\n" ); document.write( "L2) (8)=2(4)
\n" ); document.write( "8=8 L2 checks too!!! We're right!!!
\n" ); document.write( "Happy Calculating!!!
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