document.write( "Question 254478: Use the substitution method to solve the linear system given. Express
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document.write( " the answer as an ordered pair of the form (x,y)
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document.write( " x + y = 5
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document.write( " 2x + y = 6 \n" );
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Algebra.Com's Answer #186819 by PRMath(133)![]() ![]() ![]() You can put this solution on YOUR website! x + y = 5 \n" ); document.write( " 2x + y = 6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "What if you took the first equation and solved for \"X\". Let's do that. Let's take the first equation and solve for \"X\".\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x + y = 5(first equation) \n" ); document.write( "x = 5 - y (subtract y from both sides to isolate/solve for \"X\")\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now that you know x = 5 - y, you can SUBSTITUTE 5 - y into the 2nd equation, where the \"X\" variable is.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " 2x + y = 6 (2nd original equation) \n" ); document.write( "2(5 - y) + y = 6 (see where \"X\" was replaced with 5 - y)? \n" ); document.write( "10 - 2y + y = 6 (distribute the 2 and multiply 2 times 5 and then 2 times -y) \n" ); document.write( "10 - 1y = 6 (combine like terms: -2y + y = -1y) \n" ); document.write( "-1y = 6 - 10 (subtract 10 from both sides to isolate the \"Y\") \n" ); document.write( "-1y = -4 (6 - 10 = -4) \n" ); document.write( "y = 4 (divide both sides by -1 to isolate the y).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now you know that y = 4. Let's put that info into our first equation:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " x + y = 5 (original equation) \n" ); document.write( "x + 4 = 5 (see where \"Y\" was replaced with the number 4)? \n" ); document.write( "x = 5 - 4 (subtract 4 on both sides to isolate the \"X\") \n" ); document.write( "x = 1 \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now you know that x = 1. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The ordered pair then, which is in this format (x, y) is (1, 4).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Does this work in the answer? Let's \"plug\" in the x and y info into the original equations:\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " x + y = 5 (first original equation) \n" ); document.write( " 1 + 4 = 5 (equation with x and y info \"plugged\" in) \n" ); document.write( " 5 = 5 YES the ordered pair (1, 4) fits in this equation and makes it true.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " 2x + y = 6 (second original equation) \n" ); document.write( " 2(1) + 4 = 6 (equation with x and y info \"plugged\" in) \n" ); document.write( "2 + 4 = 6 \n" ); document.write( "6 = 6 YES the ordered pair (1,4) fits into this equation as well and makes it true. \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I hope this is helpful to you. :-) \n" ); document.write( " |