(x+y)^5 Binomial Theorem

3 min read Jul 03, 2024
(x+y)^5 Binomial Theorem

The Binomial Theorem: Expanding (x+y)^5

The binomial theorem is a powerful tool in algebra that allows us to expand expressions of the form (x+y)^n, where n is a positive integer. In this article, we will focus on expanding (x+y)^5 using the binomial theorem.

The Binomial Theorem Formula

The binomial theorem formula is given by:

(x+y)^n = ∑[from k=0 to n] (n choose k) * x^(n-k) * y^k

where (n choose k) is the binomial coefficient, which can be calculated using the formula:

(n choose k) = n! / (k!(n-k)!)

Expanding (x+y)^5

To expand (x+y)^5, we can use the binomial theorem formula with n=5. We get:

(x+y)^5 = ∑[from k=0 to 5] (5 choose k) * x^(5-k) * y^k

Using the formula for the binomial coefficient, we can calculate the values of (5 choose k) as follows:

  • (5 choose 0) = 5! / (0!(5-0)!) = 1
  • (5 choose 1) = 5! / (1!(5-1)!) = 5
  • (5 choose 2) = 5! / (2!(5-2)!) = 10
  • (5 choose 3) = 5! / (3!(5-3)!) = 10
  • (5 choose 4) = 5! / (4!(5-4)!) = 5
  • (5 choose 5) = 5! / (5!(5-5)!) = 1

Now, we can plug these values into the binomial theorem formula:

(x+y)^5 = x^5 + 5x^4y + 10x^3y^2 + 10x^2y^3 + 5xy^4 + y^5

Simplifying the Expansion

We can simplify the expansion by combining like terms:

(x+y)^5 = x^5 + 5x^4y + 10x^3y^2 + 10x^2y^3 + 5xy^4 + y^5

This is the final expansion of (x+y)^5 using the binomial theorem.

Conclusion

The binomial theorem is a powerful tool for expanding expressions of the form (x+y)^n. By using the formula and calculating the binomial coefficients, we can expand (x+y)^5 to get a simplified expression. This expansion can be useful in a variety of mathematical and real-world applications.

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