document.write( "Question 114213: Factor the trinomial completely.\r
\n" ); document.write( "\n" ); document.write( "2a to the 3rd power - 52a squared b + 96ab squared
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Algebra.Com's Answer #83127 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\"2a%5E3-52a%5E2b%2B96ab%5E2\" Start with the given expression\r
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\n" ); document.write( "\n" ); document.write( "\"2a%28a%5E2-26ab%2B48b%5E2%29\" Factor out the GCF \"2a\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's focus on the inner expression \"a%5E2-26ab%2B48b%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "Looking at \"a%5E2-26ab%2B48b%5E2\" we can see that the first term is \"a%5E2\" and the last term is \"48b%5E2\" where the coefficients are 1 and 48 respectively.\r
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\n" ); document.write( "\n" ); document.write( "Now multiply the first coefficient 1 and the last coefficient 48 to get 48. Now what two numbers multiply to 48 and add to the middle coefficient -26? Let's list all of the factors of 48:\r
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\n" ); document.write( "\n" ); document.write( "Factors of 48:\r
\n" ); document.write( "\n" ); document.write( "1,2,3,4,6,8,12,16,24,48\r
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\n" ); document.write( "\n" ); document.write( "-1,-2,-3,-4,-6,-8,-12,-16,-24,-48 ...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 48\r
\n" ); document.write( "\n" ); document.write( "1*48\r
\n" ); document.write( "\n" ); document.write( "2*24\r
\n" ); document.write( "\n" ); document.write( "3*16\r
\n" ); document.write( "\n" ); document.write( "4*12\r
\n" ); document.write( "\n" ); document.write( "6*8\r
\n" ); document.write( "\n" ); document.write( "(-1)*(-48)\r
\n" ); document.write( "\n" ); document.write( "(-2)*(-24)\r
\n" ); document.write( "\n" ); document.write( "(-3)*(-16)\r
\n" ); document.write( "\n" ); document.write( "(-4)*(-12)\r
\n" ); document.write( "\n" ); document.write( "(-6)*(-8)\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 -26? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -26\r
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First NumberSecond NumberSum
1481+48=49
2242+24=26
3163+16=19
4124+12=16
686+8=14
-1-48-1+(-48)=-49
-2-24-2+(-24)=-26
-3-16-3+(-16)=-19
-4-12-4+(-12)=-16
-6-8-6+(-8)=-14
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\n" ); document.write( "\n" ); document.write( "From this list we can see that -2 and -24 add up to -26 and multiply to 48\r
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\n" ); document.write( "\n" ); document.write( "Now looking at the expression \"a%5E2-26ab%2B48b%5E2\", replace \"-26ab\" with \"-2ab%2B-24ab\" (notice \"-2ab%2B-24ab\" adds up to \"-26ab\". So it is equivalent to \"-26ab\")\r
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\n" ); document.write( "\n" ); document.write( "\"a%5E2%2Bhighlight%28-2ab%2B-24ab%29%2B48b%5E2\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's factor \"a%5E2-2ab-24ab%2B48b%5E2\" by grouping:\r
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\n" ); document.write( "\n" ); document.write( "\"%28a%5E2-2ab%29%2B%28-24ab%2B48b%5E2%29\" Group like terms\r
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\n" ); document.write( "\n" ); document.write( "\"a%28a-2b%29-24b%28a-2b%29\" Factor out the GCF of \"a\" out of the first group. Factor out the GCF of \"-24b\" out of the second group\r
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\n" ); document.write( "\n" ); document.write( "\"%28a-24b%29%28a-2b%29\" Since we have a common term of \"a-2b\", we can combine like terms\r
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\n" ); document.write( "\n" ); document.write( "So \"a%5E2-2ab-24ab%2B48b%5E2\" factors to \"%28a-24b%29%28a-2b%29\"\r
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\n" ); document.write( "\n" ); document.write( "So this also means that \"a%5E2-26ab%2B48b%5E2\" factors to \"%28a-24b%29%28a-2b%29\" (since \"a%5E2-26ab%2B48b%5E2\" is equivalent to \"a%5E2-2ab-24ab%2B48b%5E2\")\r
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\n" ); document.write( "\n" ); document.write( "\"2a%28a-24b%29%28a-2b%29\"Now reintroduce the GCF back in\r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So \"2a%5E3-52a%5E2b%2B96ab%5E2\" factors to \"2a%28a-24b%29%28a-2b%29\"
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