document.write( "Question 117084: Solve the system by substitution.
\n" ); document.write( " x – 4y = –9
\n" ); document.write( " 2x + 2y = 12
\n" ); document.write( "Show all work
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Algebra.Com's Answer #86898 by misscrt(37)\"\" \"About 
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Solve the system by substitution.
\n" ); document.write( " x – 4y = –9 (Eqn 1)
\n" ); document.write( " 2x + 2y = 12 (Eqn 2)
\n" ); document.write( "Show all work\r
\n" ); document.write( "\n" ); document.write( "First, solve Eqn 1 for x:\r
\n" ); document.write( "\n" ); document.write( "x = -9 +4y (Eqn 3)\r
\n" ); document.write( "\n" ); document.write( "Then, plug Eqn 3 into Eqn 2:\r
\n" ); document.write( "\n" ); document.write( "2(-9+4y) + 2y = 12\r
\n" ); document.write( "\n" ); document.write( "-18 + 8y + 2y = 12\r
\n" ); document.write( "\n" ); document.write( "Combine like terms:\r
\n" ); document.write( "\n" ); document.write( "-18 + 10y = 12\r
\n" ); document.write( "\n" ); document.write( "Add 18 to both sides:\r
\n" ); document.write( "\n" ); document.write( "-18+18 + 10y = 12 + 18\r
\n" ); document.write( "\n" ); document.write( "10y = 30\r
\n" ); document.write( "\n" ); document.write( "y = 30/10 = 3\r
\n" ); document.write( "\n" ); document.write( "Now find x using Eqn 3:\r
\n" ); document.write( "\n" ); document.write( "x = -9 +4(3)\r
\n" ); document.write( "\n" ); document.write( "x = -9 + 12\r
\n" ); document.write( "\n" ); document.write( "x = 3\r
\n" ); document.write( "\n" ); document.write( "Hope that helps.\r
\n" ); document.write( "\n" ); document.write( "misscrt\r
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