document.write( "Question 61390: Solve the system by substitution. 3x + 3y = 6
\n" ); document.write( " y = –4x – 10 \n" ); document.write( "
Algebra.Com's Answer #42335 by funmath(2933)\"\" \"About 
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Solve the system by substitution.
\n" ); document.write( "E1: 3x+3y=6
\n" ); document.write( "E2: y=–4x–10
\n" ); document.write( ":
\n" ); document.write( "Substitute -4x-10 in for y in E1 and solve for x.
\n" ); document.write( "3x+3(-4x-10)=6
\n" ); document.write( "3x-12x-30=6
\n" ); document.write( "-9x-30=6
\n" ); document.write( "-9x-30+30=30+6
\n" ); document.write( "-9x=36
\n" ); document.write( "\"-9x%2F-9=36%2F-9\"
\n" ); document.write( "x=-4
\n" ); document.write( "Substitute -4 in for x in E2 and solve for y.
\n" ); document.write( "y=-4(-4)-10
\n" ); document.write( "y=16-10
\n" ); document.write( "y=6
\n" ); document.write( "The solution (x,y)=(-4,6)
\n" ); document.write( ":
\n" ); document.write( "Check the solution in both equations.
\n" ); document.write( "3(-4)+3(6)=6
\n" ); document.write( "-12+18=6
\n" ); document.write( "6=6 The solution checks in E1.
\n" ); document.write( ":
\n" ); document.write( "6=-4(-4)-10
\n" ); document.write( "6=16-10
\n" ); document.write( "6=6 The solution checks in E2.
\n" ); document.write( "We're right!!!
\n" ); document.write( "Happy Calculating!!! \n" ); document.write( "
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