document.write( "Question 101585: I have tried this using our book and I just don't udestand the process. My teacher is of no help, she just keeps pointing me to our book.\r
\n" ); document.write( "\n" ); document.write( "Factor each polynomial completely.\r
\n" ); document.write( "\n" ); document.write( "a) x^3y+2x^2y^2+xy^3\r
\n" ); document.write( "\n" ); document.write( "b) -4w^3-16w^2+20w\r
\n" ); document.write( "\n" ); document.write( "c) 3x^2 – 17x + 10\r
\n" ); document.write( "\n" ); document.write( "Thank you so much for any help you can provide me with. :)\r
\n" ); document.write( "\n" ); document.write( "d) -36a^2b + 21ab^2 – 3b^3
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Algebra.Com's Answer #73937 by ptaylor(2198)\"\" \"About 
You can put this solution on YOUR website!
I have tried this using our book and I just don't udestand the process. My teacher is of no help, she just keeps pointing me to our book.
\n" ); document.write( "Factor each polynomial completely.
\n" ); document.write( "a) x^3y+2x^2y^2+xy^3
\n" ); document.write( "b) -4w^3-16w^2+20w
\n" ); document.write( "c) 3x^2 – 17x + 10
\n" ); document.write( "Thank you so much for any help you can provide me with. :)
\n" ); document.write( "d) -36a^2b + 21ab^2 – 3b^3\r
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\n" ); document.write( "\n" ); document.write( "a) \"x%5E3y%2B2x%5E2y%5E2%2Bxy%5E3\" by inspection, we see that we can take an \"xy\" out of each term so lets do that:\r
\n" ); document.write( "\n" ); document.write( "\"xy%28x%5E2%2B2xy%2By%5E2%29\" Again, by inspection, we see that \"x%5E2%2B2xy%2By%5E2\" is a perfect square\"%28x%2By%29%5E2\" but we can also do the following:\r
\n" ); document.write( "\n" ); document.write( "\"xy%28x%5E2%2Bxy%2Bxy%2By%5E2%29\" and we can re-write this as follows:\r
\n" ); document.write( "\n" ); document.write( "\"xy%28x%28x%2By%29%2By%28x%2By%29%29\" now we can factor out an\"%28x%2By%29\" and we get:\r
\n" ); document.write( "\n" ); document.write( "\"xy%28x%2By%29%28x%2By%29\" or
\n" ); document.write( "\"xy%28x%2By%29%5E2\"------------------ans\r
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\n" ); document.write( "\n" ); document.write( "b) \"-4w%5E3-16w%5E2%2B20w+\" by inspection, we see that we can take a \"-4w\"out of each term so lets do that:\r
\n" ); document.write( "\n" ); document.write( "\"-4w%28w%5E2%2B4w-5%29\" Now we observe that \"w%5E2%2B4w-5\" is a quadratic in standard form. When we have a quadratic in standard form and the A coefficient is 1 then the B coefficient is the sum of the factors of the C coefficent. What are the factors of the C coefficient?? They can only be \"%28-5+and+%2B1%29\" or \"%28%2B5+and+-1%29\". By inspection we see that +5 and -1=+4. So now we know that: \"w%5E2%2B4w-5\"=\"%28w%2B5%29%28w-1%29\". Now putting it all back together, we have:\r
\n" ); document.write( "\n" ); document.write( "\"-4w%28w-5%29%28w%2B1%29\"---------------------ans \r
\n" ); document.write( "\n" ); document.write( "c) \"3x%5E2+%96+17x+%2B+10\" Here are the possibilities:
\n" ); document.write( "By inspection, we see that if this quadratic can be factored, then the factors must be of the form (a-b)(c-d) or (c-b)(a-d). Why??? Because the last term is positive and the middle term is negative. So here are the possibilities:
\n" ); document.write( "1. \"%283x-10%29%28x-1%29\"
\n" ); document.write( "2. \"%28x-10%29%283x-1%29\"
\n" ); document.write( "3. \"%283x-5%29%28x-2%29\"
\n" ); document.write( "4. \"%28x-5%29%283x-2%29\"\r
\n" ); document.write( "\n" ); document.write( "Expanding each of the above using the FOIL crutch (First, Inner, Outer, Last) we get:\r
\n" ); document.write( "\n" ); document.write( "1.\"3x%5E2-10x-3x%2B10\"-----------------NO!!! inner term is -13x
\n" ); document.write( "2.\"3x%5E2-30x-x%2B10\"------------------NO!!! inner term is -31x
\n" ); document.write( "3.\"3x%5E2-5x-2x%2B10\"-------------------NO!!!! inner term is -7x
\n" ); document.write( "4.\"3x%5E2-15x-2x%2B10\"----------------BINGO!!!!!!!\r
\n" ); document.write( "\n" ); document.write( "\"%28x-5%29%283x-2%29\"-----------------------ans\r
\n" ); document.write( "\n" ); document.write( "d) \"-36a%5E2b%2B21ab%5E2-3b%5E3\" By inspection, we see that we can take a -3b out of each term:\r
\n" ); document.write( "\n" ); document.write( "\"-3b%2812a%5E2-7ab%2Bb%5E2%29\" Now use the approach that was used in (c) above and find the factors for \"12a%5E2-7ab%2Bb%5E2\" . I bet you can do it!!!!!\r
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\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor\r
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