document.write( "Question 620290: How would I solve this equation using multiplication with the addition method? Also by using elimination..not substitution.
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document.write( "5x - 2y = 4
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document.write( "3x + y = 9 \n" );
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Algebra.Com's Answer #390069 by math-vortex(648)![]() ![]() You can put this solution on YOUR website! Hi, there-- \n" ); document.write( ". \n" ); document.write( "Using multiplication with addition is the elimination method. Substitution is a different method. \n" ); document.write( ". \n" ); document.write( "Elimination Method \n" ); document.write( ". \n" ); document.write( "I notice that the first equation has a -2y and the second equation has a y. I'm going to MULTIPLY every term in the second equation by 2. Then I will ADD the two equations together to ELIMINATE the y-term. \n" ); document.write( ". \n" ); document.write( "5x - 2y = 4 ==> 5x - 2y = 4 \n" ); document.write( "3x + y = 9 ===> 6x + 2y = 18 \n" ); document.write( ". \n" ); document.write( "Add the two equations together. Notice that -2y and 2y cancel each other out because their sum is 0. Since 5x+6x=11 and 4+18=22, we have \n" ); document.write( "11x = 22 \n" ); document.write( ". \n" ); document.write( "Simplify. \n" ); document.write( "x=2 \n" ); document.write( ". \n" ); document.write( "Now substitute 2 for x in either equation to find the y-value. I'll use the first. \n" ); document.write( ". \n" ); document.write( "5x-2y=4 \n" ); document.write( "5(2)-2y=4 \n" ); document.write( "10-2y=4 \n" ); document.write( "-2y=-6 \n" ); document.write( "y=3 \n" ); document.write( ". \n" ); document.write( "Since x=2 and y=3, the ordered pair (2,3) in the solution to this system. \n" ); document.write( ". \n" ); document.write( "Remember to check this ordered pair in the original equations to make sure you didn't make a error somewhere. \n" ); document.write( ". \n" ); document.write( "5x - 2y = 4 \n" ); document.write( "5(2)-2(3) = 4 \n" ); document.write( "10-6 = 4 \n" ); document.write( "4 = 4 Check! \n" ); document.write( ". \n" ); document.write( "3x + y = 9 \n" ); document.write( "3(2) +(3) = 9 \n" ); document.write( "6 + 3 = 9 \n" ); document.write( "9 = 9 Check! \n" ); document.write( ". \n" ); document.write( "Hope this helps. Feel free to email if you still have questions about this. \n" ); document.write( ". \n" ); document.write( "Ms. Figgy \n" ); document.write( "math.in.the.vortex@gmail.com \n" ); document.write( " |