document.write( "Question 202846: Solve. e^(4x^2+12x+9)= 1
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #153009 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"e%5E%284x%5E2%2B12x%2B9%29=1\" Start with the given equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"ln%28e%5E%284x%5E2%2B12x%2B9%29%29=ln%281%29\" Take the natural log of both sides\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"4x%5E2%2B12x%2B9=ln%281%29\" Evaluate the natural log of \"e%5E%284x%5E2%2B12x%2B9%29\" to get \"4x%5E2%2B12x%2B9\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"4x%5E2%2B12x%2B9=0\" Evaluate the natural log of 1 to get 0\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"4x%5E2%2B12x%2B9\" is in the form of \"Ax%5E2%2BBx%2BC\" where \"A=4\", \"B=12\", and \"C=9\"\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-%2812%29+%2B-+sqrt%28+%2812%29%5E2-4%284%29%289%29+%29%29%2F%282%284%29%29\" Plug in \"A=4\", \"B=12\", and \"C=9\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12+%2B-+sqrt%28+144-4%284%29%289%29+%29%29%2F%282%284%29%29\" Square \"12\" to get \"144\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12+%2B-+sqrt%28+144-144+%29%29%2F%282%284%29%29\" Multiply \"4%284%29%289%29\" to get \"144\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12+%2B-+sqrt%28+0+%29%29%2F%282%284%29%29\" Subtract \"144\" from \"144\" to get \"0\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12+%2B-+sqrt%28+0+%29%29%2F%288%29\" Multiply \"2\" and \"4\" to get \"8\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12+%2B-+0%29%2F%288%29\" Take the square root of \"0\" to get \"0\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12+%2B+0%29%2F%288%29\" or \"x+=+%28-12+-+0%29%2F%288%29\" Break up the expression. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-12%29%2F%288%29\" or \"x+=++%28-12%29%2F%288%29\" Combine like terms. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+-3%2F2\" or \"x+=+-3%2F2\" Simplify. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the only solution is \"x+=+-3%2F2\"
\n" ); document.write( "
\n" );