Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
10. Combinatorics & Probability
Combinatorics
Problem 33
Textbook Question
In Exercises 31–38, write the first three terms in each binomial expansion, expressing the result in simplified form. (x - 2y)^10
![](/channels/images/assetPage/verifiedSolution.png)
1
<insert step 1: Identify the binomial expression and the power. Here, the binomial is \((x - 2y)\) and the power is 10.>
<insert step 2: Use the Binomial Theorem, which states that \((a + b)^n = \sum_{k=0}^{n} \binom{n}{k} a^{n-k} b^k\), to expand the expression.>
<insert step 3: For the first term, set \(k = 0\): \(\binom{10}{0} (x)^{10} (-2y)^0\). Simplify this term.>
<insert step 4: For the second term, set \(k = 1\): \(\binom{10}{1} (x)^{9} (-2y)^1\). Simplify this term.>
<insert step 5: For the third term, set \(k = 2\): \(\binom{10}{2} (x)^{8} (-2y)^2\). Simplify this term.>
Recommended similar problem, with video answer:
![](/channels/images/assetPage/verifiedSolution.png)
This video solution was recommended by our tutors as helpful for the problem above
Video duration:
7mPlay a video:
Was this helpful?
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 for expanding expressions of the form (a + b)^n, where n is a non-negative integer. It states that (a + b)^n can be expressed as the sum of terms in the form of C(n, k) * a^(n-k) * b^k, where C(n, k) is the binomial coefficient. This theorem is essential for determining the coefficients and terms in the expansion of binomials.
Recommended video:
Guided course
Special Products - Cube Formulas
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 without regard to the order of selection. They can be calculated using the formula C(n, k) = n! / (k!(n-k)!), where '!' denotes factorial. These coefficients are crucial in the expansion of binomials as they determine the weight of each term in the expansion.
Recommended video:
Guided course
Special Products - Cube Formulas
Simplification of Expressions
Simplification involves reducing expressions to their simplest form by combining like terms and eliminating unnecessary components. In the context of binomial expansions, this means organizing the terms produced by the expansion and ensuring that they are expressed in a clear and concise manner. This step is vital for presenting the final result in a way that is easy to interpret and use.
Recommended video:
Guided course
Introduction to Algebraic Expressions
Watch next
Master Fundamental Counting Principle with a bite sized video explanation from Callie
Start learning