document.write( "Question 624779: solve for x: 4x(x-5)-5x(x-4)=-1 \n" ); document.write( "
Algebra.Com's Answer #393054 by reynard2007(52)\"\" \"About 
You can put this solution on YOUR website!
Here's how I did it:\r
\n" ); document.write( "\n" ); document.write( "\"4x%28x-5%29++-++5x%28x-4%29+=+-1\" This is given\r
\n" ); document.write( "\n" ); document.write( "\"4x%5E2-20x+-+5x%5E2%2B20x=-1\" Distribute 4x and -5x to the contents of the parenthesis next to them. DPMA?
\n" ); document.write( "\"-x%5E2=-1\" Add like terms: \"4x%5E2%2B-5x%5E2\" and \"-20x%2B20x\"
\n" ); document.write( "\"-x%5E2%2B1=0\" Transpose -1 to the other side of the equation, which makes it positive
\n" ); document.write( "\"x%5E2-1=0\" In solving equations like this, oyu are allowed to multiply a number to both sides of the equation, so long as you do it for both sides of the equation. Here, multiply -1 to both sides turning \"-x%5E2\" to positive \"x%5E2\" and \"%2B1\" to \"-1\"\r
\n" ); document.write( "\n" ); document.write( "If you are familiar with the special product called DOTS (Difference of two squares) this will make solving the equation easier. Given \"x%5E2-1=0\" you can factor it to \"%28x%2B1%29\" and \"%28x-1%29\". Equate both of these to 0 and you get:\r
\n" ); document.write( "\n" ); document.write( "\"x%2B1=0\" -->\"x=-1\"
\n" ); document.write( "and
\n" ); document.write( "\"x-1=0\" --> \"x=1\"\r
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\n" ); document.write( "\n" ); document.write( "I can't find a way to reply to your comment so, I just edited this.
\n" ); document.write( "when \"x=1\";\r
\n" ); document.write( "\n" ); document.write( "\"4%2A%281%29%2A%28%281%29-5%29++-++5%2A%281%29%2A%28%281%29-4%29+=+-1\"
\n" ); document.write( "\"4%2A%28-4%29-5%2A%28-3%29=-1\"
\n" ); document.write( "\"-16-%28-15%29=-16%2B15=-1\"\r
\n" ); document.write( "\n" ); document.write( "You can try the same with \"x=-1\"\r
\n" ); document.write( "\n" ); document.write( "Hope this does it for your problem.\r
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