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 January 16th, 2015, 02:15 PM #1 Member   Joined: Apr 2014 From: Missouri Posts: 39 Thanks: 1 Coefficient find in expansion of a term Hi I just had this question. What is the coefficient of the term x^18 in the expansion of (x^5+x^2+x)^10. In the solve, they told to find the how x^18 can be formed with x^5, x^2 and x. Like 18= 2*5+8*1.........Now i understand why the sum should be 18 but why the summation of multiplier needs to be exactly 10 like the initial power? Why we can not have 18=3*5+3*1???????????? Thanks in advance January 17th, 2015, 02:47 PM   #2
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 Originally Posted by Shen Hi I just had this question. What is the coefficient of the term x^18 in the expansion of (x^5+x^2+x)^10. In the solve, they told to find the how x^18 can be formed with x^5, x^2 and x. Like 18= 2*5+8*1.........Now i understand why the sum should be 18 but why the summation of multiplier needs to be exactly 10 like the initial power? Why we can not have 18=3*5+3*1???????????? Thanks in advance
When you expand polynomials to a power, those (sum of powers = initial power) are the only terms you will get. Try binomial to see what happens. Tags coefficient, expansion, find, term Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Threads Thread Thread Starter Forum Replies Last Post wilhelm Applied Math 1 November 28th, 2012 06:00 AM RuneBoggler Algebra 2 May 10th, 2011 11:14 AM rowdy3 Algebra 2 November 11th, 2010 10:01 PM davedave Algebra 1 November 10th, 2009 12:26 AM rowdy3 Calculus 1 December 31st, 1969 04:00 PM

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