document.write( "Question 625481: How would you solve for x, using the quadratic formula?\r
\n" ); document.write( "\n" ); document.write( "x^2+x-1=0\r
\n" ); document.write( "\n" ); document.write( "Thank you!
\n" ); document.write( "

Algebra.Com's Answer #393552 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( "\"x%5E2%2Bx-1=0\" Start with the given equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"x%5E2%2Bx-1\" is in the form of \"Ax%5E2%2BBx%2BC\" where \"A=1\", \"B=1\", and \"C=-1\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for \"x\":\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-B+%2B-+sqrt%28+B%5E2-4AC+%29%29%2F%282A%29\" Start with the quadratic formula\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%281%29%28-1%29+%29%29%2F%282%281%29%29\" Plug in \"A=1\", \"B=1\", and \"C=-1\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1-4%281%29%28-1%29+%29%29%2F%282%281%29%29\" Square \"1\" to get \"1\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1--4+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-1%29\" to get \"-4\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1%2B4+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%281--4%29\" as \"sqrt%281%2B4%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+5+%29%29%2F%282%281%29%29\" Add \"1\" to \"4\" to get \"5\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+5+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1%2Bsqrt%285%29%29%2F%282%29\" or \"x+=+%28-1-sqrt%285%29%29%2F%282%29\" Break up the expression. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the solutions are \"x+=+%28-1%2Bsqrt%285%29%29%2F%282%29\" or \"x+=+%28-1-sqrt%285%29%29%2F%282%29\" \r
\n" ); document.write( "\n" ); document.write( "--------------------------------------------------------------------------------------------------------------
\n" ); document.write( "If you need more help, email me at jim_thompson5910@hotmail.com\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Jim
\n" ); document.write( "--------------------------------------------------------------------------------------------------------------
\n" ); document.write( "
\n" ); document.write( "
\n" );