document.write( "Question 173267: I am having a problem understanding how to solve a system byusing substitution.
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document.write( "Here are few of the problems I'm facing. Could you please explain them to me?
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document.write( "1. y = -3x+19
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document.write( " y + 2x-1\r
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document.write( "2. y = x +4
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document.write( " 3x-2y=6\r
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document.write( "3. 2x-y = 4
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document.write( " 2x-y=3\r
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document.write( "I've looked at tons of reasons on how these problems work, and none of them make sense. The ones I've looked at are not specific enough on the what, why and how of the problem.
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document.write( "Thanks for your help!
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document.write( "Angela \n" );
document.write( "
Algebra.Com's Answer #128087 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! The goal of solving ANY system of equations with 2 variables is to eliminate one variable so you can solve for the other variable. To eliminate one variable, simply \"substitute\" an expression in terms of the other variable. \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "# 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: I'm assuming that the second equation is \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now we can solve for \"x\".\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "--------------------------------\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "=========================================\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the solutions are \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "which form the ordered pair (4,7)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the system is consistent and independent.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "# 2\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now we can solve for \"x\".\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-------------------------------------------\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "=========================================\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the solutions are \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "which form the ordered pair (14,18)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the system is consistent and independent.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "# 3\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to solve for y.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So let's isolate y in the first equation\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "---------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since this equation is NEVER true for any x value, this means there are no solutions.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the system is inconsistent. \n" ); document.write( " |