document.write( "Question 648116: 4x squared-4x-99=0 \n" ); document.write( "
Algebra.Com's Answer #406564 by Algebraic(50)\"\" \"About 
You can put this solution on YOUR website!
Original problem: \"4x%5E2-4x-99\"\r
\n" ); document.write( "\n" ); document.write( "We're going to be factoring this to extract the roots (what 'x' equals)\r
\n" ); document.write( "\n" ); document.write( "Step 1: We must find two numbers that when '4' and '-99' multiply, will divide to give you '-4' in the middle.\r
\n" ); document.write( "\n" ); document.write( "\"4x%5E2-4x-99\"\r
\n" ); document.write( "\n" ); document.write( "You have quite a few number of combinations:\r
\n" ); document.write( "\n" ); document.write( "The \"4x%5E2\" can be broken up into\r
\n" ); document.write( "\n" ); document.write( "\"%284x++%29%28x++%29\"
\n" ); document.write( "or
\n" ); document.write( "\"%282x++%29%282x++%29\"\r
\n" ); document.write( "\n" ); document.write( "We know that '-99' has six factors, and these include:\r
\n" ); document.write( "\n" ); document.write( "1 x 99, 3 x 33, and 9 x 11\r
\n" ); document.write( "\n" ); document.write( "Step 2: Let's start trying to see what will work and not work (trial and error method)\r
\n" ); document.write( "\n" ); document.write( "We know that regardless of signs, none of the factors of '-99' will be able to multiply here to give you a '-4' in the middle using this equation:\r
\n" ); document.write( "\n" ); document.write( "\"%284x+%2B+3+%29%28x+-+33+%29\" ---> Does not work, gives you \"-33x+%2B+3x\" in the middle
\n" ); document.write( "\"%284x+-+3+%29%28x+%2B+33+%29\" ---> Does not work, gives you \"33x+-+3x\" in the middle
\n" ); document.write( "\"%284x+%2B++1+%29%28x+-+99+%29\" ---> Does not work, gives you \"-396x+%2B+x\" in the middle
\n" ); document.write( "\"%284x+-+1+%29%28x+%2B+99+%29\" ---> Does not work, gives you \"396x+-+x\" in the middle
\n" ); document.write( "\"%284x+%2B+9+%29%28x+-+11+%29\" ---> Does not work, gives you \"-44x+%2B+9x\" in the middle
\n" ); document.write( "\"%284x+-+9+%29%28x+%2B+11+%29\" ---> Does not work, gives you \"44x+-+9x\" in the middle\r
\n" ); document.write( "\n" ); document.write( "Now that we know that the \"%284x++%29%28x++%29\" equation won't work, let's move on to the other equation that could possibly work..\r
\n" ); document.write( "\n" ); document.write( "Step 3: Let's start trying to see what will work and not work (trial and error method)\r
\n" ); document.write( "\n" ); document.write( "We know that '-99' has six factors, and these include:\r
\n" ); document.write( "\n" ); document.write( "1 x 99, 3 x 33, and 9 x 11\r
\n" ); document.write( "\n" ); document.write( "We know that regardless of signs, none of the factors of '-99' will be able to multiply here to give you a '-4' in the middle using this equation:\r
\n" ); document.write( "\n" ); document.write( "\"%282x+%2B+1+%29%282x+-+99+%29\" ---> Does not work, gives you \"-198x+%2B+2x\" in the middle
\n" ); document.write( "\"%282x+-+1+%29%282x+%2B+99+%29\" ---> Does not work, gives you \"198x+-+2x\" in the middle
\n" ); document.write( "\"%282x+%2B+3+%29%282x+-+33+%29\" ---> Does not work, gives you \"-66x+%2B+6x\" in the middle
\n" ); document.write( "\"%282x+-+3+%29%282x+%2B+33+%29\" ---> Does not work, gives you \"66x+-+6x\" in the middle
\n" ); document.write( "\"%282x+%2B+9+%29%282x+-+11+%29\" ---> Works!! Gives you \"-22x+%2B+18x\" in the middle, which is equivalent to '-4x'
\n" ); document.write( "\"%282x+-+9+%29%282x+%2B+11+%29\" ---> Does not work, gives you \"22x+-+18x\" in the middle\r
\n" ); document.write( "\n" ); document.write( "So.. now we know that the factored version of the equation you provided is:\r
\n" ); document.write( "\n" ); document.write( "\"%282x+%2B+9+%29%282x+-+11+%29\"\r
\n" ); document.write( "\n" ); document.write( "To get the roots, you must set each parenthesis equal to zero like so..\r
\n" ); document.write( "\n" ); document.write( "Step 1: Set each parenthesis equal to zero\r
\n" ); document.write( "\n" ); document.write( "\"%282x+%2B+9+%29=0\"
\n" ); document.write( "\"%282x+-+11+%29=0\"\r
\n" ); document.write( "\n" ); document.write( "Step 2: Let's solve each one at a time\r
\n" ); document.write( "\n" ); document.write( "\"%282x+%2B+9+%29=0\"\r
\n" ); document.write( "\n" ); document.write( "Subtract '9' from both sides to get the '2x' by itself\r
\n" ); document.write( "\n" ); document.write( "\"%282x+%2B+9+%29=0\"
\n" ); document.write( "\"2x=-9\"\r
\n" ); document.write( "\n" ); document.write( "Divide both sides by '2' to get 'x' by itself\r
\n" ); document.write( "\n" ); document.write( "\"2x=-9\"
\n" ); document.write( "\"x=%28-9%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "First root is \"x=%28-9%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "Step 3: Let's find the other root\r
\n" ); document.write( "\n" ); document.write( "\"%282x+-+11+%29=0\"\r
\n" ); document.write( "\n" ); document.write( "Add '11' to both sides to get the '2x' by itself\r
\n" ); document.write( "\n" ); document.write( "\"%282x+-+11+%29=0\"
\n" ); document.write( "\"2x=11\"\r
\n" ); document.write( "\n" ); document.write( "Divide both sides by '2' to get the 'x' by itself\r
\n" ); document.write( "\n" ); document.write( "\"2x=11\"
\n" ); document.write( "\"x=%2811%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "Second root is \"x=%2811%2F2%29\"\r
\n" ); document.write( "\n" ); document.write( "So, the factored version of this equation is \"%282x+%2B+9+%29%282x+-+11+%29\" and its roots are \"x=%28-9%2F2%29\" and \"x=%2811%2F2%29\"\r
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