MHB Binomial Expansion Part I: Find Formula for 8th Power - 65 chars

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The discussion focuses on finding the binomial expansion for four different binomials raised to the 8th power. The expansions for (x + y), (w + z), (x - y), and (2a + 3b) are explored, with emphasis on how the first expansion can serve as a formula for the others. Participants clarify that for (w + z), x equals w and y equals z; for (x - y), x remains x while y becomes -y; and for (2a + 3b), x is 2a and y is 3b. The importance of correctly substituting terms into the expansions is highlighted, particularly ensuring that powers apply to the entire term. Understanding these substitutions is crucial for accurately applying the binomial theorem.
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Part I. Write out the binomial expansion for each binomial raised to the 8th power.
1. (x + y) 2. (w + z) 3. (x - y) 4. (2a + 3b)
Part II. Now explain how your answer for #1 could be used as a formula to help you answer each of the other items. In each case, for #2, 3 and 4, tell what would x equal and what would y equal.

I did the binomial expansions. Those are easy, but how can you find the value?
 
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toyjoha said:
Part I. Write out the binomial expansion for each binomial raised to the 8th power.
1. (x + y) 2. (w + z) 3. (x - y) 4. (2a + 3b)
Part II. Now explain how your answer for #1 could be used as a formula to help you answer each of the other items. In each case, for #2, 3 and 4, tell what would x equal and what would y equal.

I did the binomial expansions. Those are easy, but how can you find the value?
http://lmgtfy.com/?q=binomial+coefficient
 
What did you get for the expansion of (x+y)^5? What happens when you substitute another term for x and y, say x=3c and y=2d into the expansion of (x+y)^5? Remember when you substitute you must pay close attention to apply any powers to the whole term, not just the variable. So if you see x^5 and you substitute x=3c, then the substituted expression would be (3c)^5, NOT 3(c^5).
 
toyjoha said:
Part I. Write out the binomial expansion for each binomial raised to the 8th power.
1. (x + y) 2. (w + z) 3. (x - y) 4. (2a + 3b)
Part II. Now explain how your answer for #1 could be used as a formula to help you answer each of the other items. In each case, for #2, 3 and 4, tell what would x equal and what would y equal.

I did the binomial expansions. Those are easy, but how can you find the value?
They are not asking for "values". To use your answer to (1) to get (2) let x= w and let y= z. Similarly for (3) x stays x but y becomes -y. Finally, for (4) let x= 2a, y= 3b.
 
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