document.write( "Question 145612: factor x^2+7x+10=0 \n" ); document.write( "
Algebra.Com's Answer #106261 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Looking at \"x%5E2%2B7x%2B10\" we can see that the first term is \"x%5E2\" and the last term is \"10\" where the coefficients are 1 and 10 respectively.\r
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\n" ); document.write( "\n" ); document.write( "Now multiply the first coefficient 1 and the last coefficient 10 to get 10. Now what two numbers multiply to 10 and add to the middle coefficient 7? Let's list all of the factors of 10:\r
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\n" ); document.write( "\n" ); document.write( "Factors of 10:\r
\n" ); document.write( "\n" ); document.write( "1,2,5,10\r
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\n" ); document.write( "\n" ); document.write( "-1,-2,-5,-10 ...List the negative factors as well. This will allow us to find all possible combinations\r
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\n" ); document.write( "\n" ); document.write( "These factors pair up and multiply to 10\r
\n" ); document.write( "\n" ); document.write( "1*10\r
\n" ); document.write( "\n" ); document.write( "2*5\r
\n" ); document.write( "\n" ); document.write( "(-1)*(-10)\r
\n" ); document.write( "\n" ); document.write( "(-2)*(-5)\r
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\n" ); document.write( "\n" ); document.write( "note: remember two negative numbers multiplied together make a positive number\r
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\n" ); document.write( "\n" ); document.write( "Now which of these pairs add to 7? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 7\r
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First NumberSecond NumberSum
1101+10=11
252+5=7
-1-10-1+(-10)=-11
-2-5-2+(-5)=-7
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\n" ); document.write( "\n" ); document.write( "From this list we can see that 2 and 5 add up to 7 and multiply to 10\r
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\n" ); document.write( "\n" ); document.write( "Now looking at the expression \"x%5E2%2B7x%2B10\", replace \"7x\" with \"2x%2B5x\" (notice \"2x%2B5x\" adds up to \"7x\". So it is equivalent to \"7x\")\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2Bhighlight%282x%2B5x%29%2B10\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's factor \"x%5E2%2B2x%2B5x%2B10\" by grouping:\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%5E2%2B2x%29%2B%285x%2B10%29\" Group like terms\r
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\n" ); document.write( "\n" ); document.write( "\"x%28x%2B2%29%2B5%28x%2B2%29\" Factor out the GCF of \"x\" out of the first group. Factor out the GCF of \"5\" out of the second group\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B5%29%28x%2B2%29\" Since we have a common term of \"x%2B2\", we can combine like terms\r
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\n" ); document.write( "\n" ); document.write( "So \"x%5E2%2B2x%2B5x%2B10\" factors to \"%28x%2B5%29%28x%2B2%29\"\r
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\n" ); document.write( "\n" ); document.write( "So this also means that \"x%5E2%2B7x%2B10\" factors to \"%28x%2B5%29%28x%2B2%29\" (since \"x%5E2%2B7x%2B10\" is equivalent to \"x%5E2%2B2x%2B5x%2B10\")\r
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\n" ); document.write( "\n" ); document.write( " Answer:\r
\n" ); document.write( "\n" ); document.write( "So \"x%5E2%2B7x%2B10\" factors to \"%28x%2B5%29%28x%2B2%29\"
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