Question: Factor completely. 9, x, squared, minus, 49
9x 2 −49
1. **State the problem:** Factor the expression $$9x^2 - 49$$ completely.
2. **Recognize the form:** This is a difference of squares because $$9x^2 = (3x)^2$$ and $$49 = 7^2$$.
3. **Recall the difference of squares formula:** $$a^2 - b^2 = (a - b)(a + b)$$.
4. **Apply the formula:** Here, $$a = 3x$$ and $$b = 7$$, so
$$9x^2 - 49 = (3x)^2 - 7^2 = (3x - 7)(3x + 7)$$.
5. **Final answer:** The completely factored form is $$\boxed{(3x - 7)(3x + 7)}$$.