document.write( "Question 620290: How would I solve this equation using multiplication with the addition method? Also by using elimination..not substitution.
\n" ); document.write( "5x - 2y = 4
\n" ); document.write( "3x + y = 9
\n" ); document.write( "

Algebra.Com's Answer #390069 by math-vortex(648)\"\" \"About 
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( "
\n" );