Expanding (x-8)(x-8)
The expression (x-8)(x-8) is a product of two binomials. To expand this, we can use the FOIL method which stands for:
- First: Multiply the first terms of each binomial.
- Outer: Multiply the outer terms of the binomials.
- Inner: Multiply the inner terms of the binomials.
- Last: Multiply the last terms of each binomial.
Let's apply this method to (x-8)(x-8):
- First: x * x = x²
- Outer: x * -8 = -8x
- Inner: -8 * x = -8x
- Last: -8 * -8 = 64
Now, combine the terms: x² - 8x - 8x + 64
Finally, simplify by combining the like terms: x² - 16x + 64
Therefore, the expanded form of (x-8)(x-8) is x² - 16x + 64.
Recognizing a Special Case
This expression is a special case known as a perfect square trinomial. This is because it's the result of squaring a binomial. Notice the pattern:
- The first term is the square of the first term of the binomial (x² = x * x)
- The last term is the square of the second term of the binomial (64 = -8 * -8)
- The middle term is twice the product of the two terms of the binomial (-16x = 2 * x * -8)
Understanding this pattern can help you quickly expand similar expressions.