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Ch. 8 - Sequences, Induction, and Probability
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 9, Problem 29

Use the Binomial Theorem to expand each binomial and express the result in simplified form. (2a + b)6

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1
Identify the binomial expression to expand: \((2a + b)^6\).
Recall the Binomial Theorem formula: \(\displaystyle (x + y)^n = \sum_{k=0}^n \binom{n}{k} x^{n-k} y^k\), where \(\binom{n}{k}\) is the binomial coefficient.
In this problem, set \(x = 2a\), \(y = b\), and \(n = 6\). The expansion will be \(\sum_{k=0}^6 \binom{6}{k} (2a)^{6-k} b^k\).
Calculate each term by finding the binomial coefficient \(\binom{6}{k}\), raising \$2a\( to the power \)(6-k)\(, and \)b\( to the power \)k\(, then multiply these values together for each \)k$ from 0 to 6.
Simplify each term by applying the exponent to \$2a$ (remember to raise 2 to the power as well), and write the full expanded expression as the sum of all these simplified terms.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Binomial Theorem

The Binomial Theorem provides a formula to expand expressions of the form (x + y)^n, where n is a non-negative integer. It states that (x + y)^n equals the sum of terms C(n, k) * x^(n-k) * y^k, where C(n, k) are binomial coefficients. This theorem simplifies the expansion process without multiplying the binomial repeatedly.
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Binomial Coefficients

Binomial coefficients, denoted as C(n, k) or "n choose k," represent the number of ways to choose k elements from a set of n elements. They appear as coefficients in the binomial expansion and can be calculated using factorials or Pascal's Triangle. These coefficients determine the weight of each term in the expanded expression.
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Exponent Rules in Expansion

When expanding (2a + b)^6, each term involves powers of 2a and b whose exponents add up to 6. The exponent rules state that (xy)^n = x^n * y^n and (x^m)^n = x^(m*n). Applying these rules helps simplify each term by correctly raising coefficients and variables to their respective powers.
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