document.write( "Question 1167827: how do I solve the system of equations by the substitution method for
\n" ); document.write( "28x +7y = 12
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Algebra.Com's Answer #792415 by ikleyn(52790)\"\" \"About 
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document.write( "From the second equation, express y = -4x - 8  and substitute it into the first equation, replacing y there\r\n" );
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document.write( "    28x + 7*(-4x - 8) = 12.\r\n" );
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document.write( "Simplify\r\n" );
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document.write( "   \r\n" );
document.write( "    28x - 28x - 56 = 12\r\n" );
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document.write( "               -56 = 12.\r\n" );
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document.write( "You get a self-contradictory equation, which has no solutions.\r\n" );
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document.write( "Hence, the original system has no solutions, too.\r\n" );
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\n" ); document.write( "\n" ); document.write( "On the Substitution method, Elimination method, Determinants' method for solving the systems
\n" ); document.write( "of two linear equations in two unknowns see the lessons \r
\n" ); document.write( "\n" ); document.write( "    - Solution of the linear system of two equations in two unknowns by the Substitution method \r
\n" ); document.write( "\n" ); document.write( "    - Solution of the linear system of two equations in two unknowns by the Elimination method \r
\n" ); document.write( "\n" ); document.write( "    - Solution of the linear system of two equations in two unknowns using determinant \r
\n" ); document.write( "\n" ); document.write( "    - Geometric interpretation of the linear system of two equations in two unknowns (*)\r
\n" ); document.write( "\n" ); document.write( "    - Useful tricks when solving systems of 2 equations in 2 unknowns by the Substitution method \r
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\n" ); document.write( "\n" ); document.write( "Pay special attention to the lesson marked (*) in the list, since it contains important information, useful to you (!)\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this online textbook under the topic \"Systems of two linear equations in two unknowns\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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