document.write( "Question 1007851: On my homework it says:
\n" ); document.write( "Solve the system of equations through elimination.
\n" ); document.write( "2x-3y=21
\n" ); document.write( "-6x+2y=7\r
\n" ); document.write( "\n" ); document.write( "I have tried so many times but can't figure it out. And how do I know whether to add or subtract?
\n" ); document.write( "I'd greatly appreciate it if I could be taught HOW to solve this, not just the answer.
\n" ); document.write( "Thank You! \n" ); document.write( "
Algebra.Com's Answer #623703 by tiffany222(56)\"\" \"About 
You can put this solution on YOUR website!
2x - 3y = 21
\n" ); document.write( "-6x + 2y = 7
\n" ); document.write( "Step 1: Eliminate either x or y to solve for one value. In this problem, we will eliminate x by multiplying the first equation by 3.
\n" ); document.write( "6x - 9y = 63
\n" ); document.write( "-6x + 2y = 7
\n" ); document.write( "Step 2: Add the two equations to eliminate x and solve for y. We add because we want the x coefficient to become 0.
\n" ); document.write( "-7y = 70
\n" ); document.write( "y = -10
\n" ); document.write( "Step 3: Substitute the y value we just got into either one of the two original equations to get the x value. I decided to use the first equation, but using the second equation will also get you the right answer.
\n" ); document.write( "2x - 3y = 21
\n" ); document.write( "2x - 3(-10) = 21
\n" ); document.write( "2x + 30 = 21
\n" ); document.write( "2x = -9
\n" ); document.write( "x = -4.5\r
\n" ); document.write( "\n" ); document.write( "Final Answer:
\n" ); document.write( "x = -4.5
\n" ); document.write( "y = -10\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
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