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Consider the expression (2x^3+b/x)^8 = 256x^24 + 3072x^20 +...+kx^0... a) find b

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Final answer:

To find b, we need to analyze the constant term in the expanded expression and use the binomial theorem. By solving the equation (b/x)^8 = 256, we can determine that b = 2x.

Step-by-step explanation:

Step 1:

Expand the expression using the binomial theorem.

(2x^3 + b/x)^8 = 256x^24 + 3072x^20 + ... + kx^0



Step 2:

Apply the binomial theorem to find the coefficients of each term.



Step 3:

Look for the term that does not contain any variable, which is the constant term. In this case, it is

256x^24

. The exponent of x in this term is 24, so we know that 2x to the power of 3 should be raised to the power of 8 to get the exponent 24. That means 3 * 8 = 24. Therefore, b/x should be raised to the power of 8 to get the constant term 256.



Using this information, we can write the equation:

(b/x)^8 = 256



Step 4:

Solve for b. Taking the eighth root of both sides, we find:

b/x = 2



Multiplying both sides by x, we get:

b = 2x

User Brad Figueroa
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