document.write( "Question 264538: solve:
\n" ); document.write( "3x-2y=12
\n" ); document.write( "2x+3y=-5
\n" ); document.write( "by the addition method\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "solve:
\n" ); document.write( "2x-1y=-5
\n" ); document.write( "3x-5y=-4
\n" ); document.write( "by substitution\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "show steps please.
\n" ); document.write( "

Algebra.Com's Answer #194765 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'll do the first one to get you started.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
\n" ); document.write( "\n" ); document.write( "\"system%283x-2y=12%2C2x%2B3y=-5%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"3%283x-2y%29=3%2812%29\" Multiply the both sides of the first equation by 3.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"9x-6y=36\" Distribute and multiply.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"2%282x%2B3y%29=2%28-5%29\" Multiply the both sides of the second equation by 2.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"4x%2B6y=-10\" 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%289x-6y=36%2C4x%2B6y=-10%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( "\"%289x-6y%29%2B%284x%2B6y%29=%2836%29%2B%28-10%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%289x%2B4x%29%2B%28-6y%2B6y%29=36%2B-10\" Group like terms.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"13x%2B0y=26\" Combine like terms.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"13x=26\" Simplify.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=%2826%29%2F%2813%29\" Divide both sides by \"13\" to isolate \"x\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x=2\" 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( "\"9x-6y=36\" Now go back to the first equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"9%282%29-6y=36\" Plug in \"x=2\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"18-6y=36\" Multiply.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-6y=36-18\" Subtract \"18\" from both sides.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-6y=18\" Combine like terms on the right side.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=%2818%29%2F%28-6%29\" Divide both sides by \"-6\" to isolate \"y\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-3\" Reduce.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the solutions are \"x=2\" and \"y=-3\".\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 \"3x-2y=12\" (red) and \"2x%2B3y=-5\" (green)
\n" ); document.write( "
\n" ); document.write( "
\n" );