document.write( "Question 182609: Please Help.
\n" ); document.write( "Use elimination to solve each system of equations.
\n" ); document.write( "2X-3Y=9 -5X-3Y=30
\n" ); document.write( "

Algebra.Com's Answer #137092 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%282x-3y=9%2C-5x-3y=30%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-1%28-5x-3y%29=-1%2830%29\" Multiply the both sides of the second equation by -1.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"5x%2B3y=-30\" Distribute and multiply.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So we have the new system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%282x-3y=9%2C5x%2B3y=-30%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now add the equations together. You can do this by simply adding the two left sides and the two right sides separately like this:\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%282x-3y%29%2B%285x%2B3y%29=%289%29%2B%28-30%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%282x%2B5x%29%2B%28-3y%2B3y%29=9%2B-30\" Group like terms.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"7x%2B0y=-21\" Combine like terms.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"7x=-21\" Simplify.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=%28-21%29%2F%287%29\" Divide both sides by \"7\" to isolate \"x\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=-3\" Reduce.\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( "\"2x-3y=9\" Now go back to the first equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2%28-3%29-3y=9\" Plug in \"x=-3\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-6-3y=9\" Multiply.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-3y=9%2B6\" Add \"6\" to both sides.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-3y=15\" Combine like terms on the right side.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=%2815%29%2F%28-3%29\" Divide both sides by \"-3\" to isolate \"y\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-5\" Reduce.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So our answer is \"x=-3\" and \"y=-5\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Which form the ordered pair .\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This means that the system is consistent and independent.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Notice when we graph the equations, we see that they intersect at . So this visually verifies our answer.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Graph of \"2x-3y=9\" (red) and \"-5x-3y=30\" (green) \r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );