Understanding (k + 5)^2
(k + 5)^2 is a mathematical expression representing the square of the binomial (k + 5). This means multiplying the binomial by itself:
(k + 5)^2 = (k + 5)(k + 5)
To simplify this expression, we can use the FOIL method (First, Outer, Inner, Last). This method helps us multiply two binomials systematically.
Here's how it works:
- First: Multiply the first terms of each binomial: k * k = k^2
- Outer: Multiply the outer terms of the binomials: k * 5 = 5k
- Inner: Multiply the inner terms of the binomials: 5 * k = 5k
- Last: Multiply the last terms of each binomial: 5 * 5 = 25
Now, combine the results:
(k + 5)^2 = k^2 + 5k + 5k + 25
Finally, simplify by combining like terms:
(k + 5)^2 = k^2 + 10k + 25
Therefore, the expanded form of (k + 5)^2 is k^2 + 10k + 25.
Key Points:
- The FOIL method is a useful tool for multiplying binomials.
- Expanding a binomial square results in a trinomial (an expression with three terms).
- The coefficient of the middle term (10k) is always twice the product of the terms in the original binomial (k and 5).
- The constant term (25) is always the square of the second term in the original binomial (5).
Understanding how to expand expressions like (k + 5)^2 is essential in algebra and other areas of mathematics. It allows you to simplify expressions and solve equations more effectively.