Expanding the Expression: (x-7)(x+7)
The expression (x-7)(x+7) represents the product of two binomials. We can expand this expression using the FOIL method, which stands for First, Outer, Inner, Last.
Here's how it works:
- First: Multiply the first terms of each binomial: x * x = x²
- Outer: Multiply the outer terms of the binomials: x * 7 = 7x
- Inner: Multiply the inner terms of the binomials: -7 * x = -7x
- Last: Multiply the last terms of each binomial: -7 * 7 = -49
Now, we combine all the terms:
x² + 7x - 7x - 49
Notice that the 7x and -7x terms cancel each other out. This leaves us with:
x² - 49
This result, x² - 49, is a difference of squares.
Key takeaway: The expression (x-7)(x+7) expands to x² - 49. This demonstrates a common pattern in algebra where the product of a binomial with its conjugate results in a difference of squares.