document.write( "Question 244746: How i solve this problem 10x^2-19x+6 \n" ); document.write( "

Algebra.Com's Answer #178991 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
I'm assuming that you want to factor this.\r
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\n" ); document.write( "\n" ); document.write( "Looking at the expression $\"10x%5E2-19x%2B6\"$ , we can see that the first coefficient is $\"10\"$ , the second coefficient is $\"-19\"$ , and the last term is $\"6\"$ .\r
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\n" ); document.write( "\n" ); document.write( "Now multiply the first coefficient $\"10\"$ by the last term $\"6\"$ to get $\"%2810%29%286%29=60\"$ .\r
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\n" ); document.write( "\n" ); document.write( "Now the question is: what two whole numbers multiply to $\"60\"$ (the previous product) and add to the second coefficient $\"-19\"$ ?\r
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\n" ); document.write( "\n" ); document.write( "To find these two numbers, we need to list all of the factors of $\"60\"$ (the previous product).\r
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\n" ); document.write( "\n" ); document.write( "Factors of $\"60\"$ :\r
\n" ); document.write( "\n" ); document.write( "1,2,3,4,5,6,10,12,15,20,30,60\r
\n" ); document.write( "\n" ); document.write( "-1,-2,-3,-4,-5,-6,-10,-12,-15,-20,-30,-60\r
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\n" ); document.write( "\n" ); document.write( "Note: list the negative of each factor. 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 $\"60\"$ .\r
\n" ); document.write( "\n" ); document.write( "1*60 = 60
\n" ); document.write( "2*30 = 60
\n" ); document.write( "3*20 = 60
\n" ); document.write( "4*15 = 60
\n" ); document.write( "5*12 = 60
\n" ); document.write( "6*10 = 60
\n" ); document.write( "(-1)*(-60) = 60
\n" ); document.write( "(-2)*(-30) = 60
\n" ); document.write( "(-3)*(-20) = 60
\n" ); document.write( "(-4)*(-15) = 60
\n" ); document.write( "(-5)*(-12) = 60
\n" ); document.write( "(-6)*(-10) = 60\r
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\n" ); document.write( "\n" ); document.write( "Now let's add up each pair of factors to see if one pair adds to the middle coefficient $\"-19\"$ :\r
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First Number	Second Number	Sum
1	60	1+60=61
2	30	2+30=32
3	20	3+20=23
4	15	4+15=19
5	12	5+12=17
6	10	6+10=16
-1	-60	-1+(-60)=-61
-2	-30	-2+(-30)=-32
-3	-20	-3+(-20)=-23
-4	-15	-4+(-15)=-19
-5	-12	-5+(-12)=-17
-6	-10	-6+(-10)=-16

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\n" ); document.write( "\n" ); document.write( "From the table, we can see that the two numbers $\"-4\"$ and $\"-15\"$ add to $\"-19\"$ (the middle coefficient).\r
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\n" ); document.write( "\n" ); document.write( "So the two numbers $\"-4\"$ and $\"-15\"$ both multiply to $\"60\"$ and add to $\"-19\"$ \r
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\n" ); document.write( "\n" ); document.write( "Now replace the middle term $\"-19x\"$ with $\"-4x-15x\"$ . Remember, $\"-4\"$ and $\"-15\"$ add to $\"-19\"$ . So this shows us that $\"-4x-15x=-19x\"$ .\r
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\n" ); document.write( "\n" ); document.write( " $\"10x%5E2%2Bhighlight%28-4x-15x%29%2B6\"$ Replace the second term $\"-19x\"$ with $\"-4x-15x\"$ .\r
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\n" ); document.write( "\n" ); document.write( " $\"%2810x%5E2-4x%29%2B%28-15x%2B6%29\"$ Group the terms into two pairs.\r
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\n" ); document.write( "\n" ); document.write( " $\"2x%285x-2%29%2B%28-15x%2B6%29\"$ Factor out the GCF $\"2x\"$ from the first group.\r
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\n" ); document.write( "\n" ); document.write( " $\"2x%285x-2%29-3%285x-2%29\"$ Factor out $\"3\"$ from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.\r
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\n" ); document.write( "\n" ); document.write( " $\"%282x-3%29%285x-2%29\"$ Combine like terms. Or factor out the common term $\"5x-2\"$ \r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So $\"10x%5E2-19x%2B6\"$ factors to $\"%282x-3%29%285x-2%29\"$ .\r
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\n" ); document.write( "\n" ); document.write( "In other words, $\"10x%5E2-19x%2B6=%282x-3%29%285x-2%29\"$ .\r
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\n" ); document.write( "\n" ); document.write( "Note: you can check the answer by expanding $\"%282x-3%29%285x-2%29\"$ to get $\"10x%5E2-19x%2B6\"$ or by graphing the original expression and the answer (the two graphs should be identical).
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