Question: Factor completely. 100, minus, 121, x, squared
100−121x^2
1. **State the problem:** Factor the expression $$100 - 121x^2$$ completely.
2. **Recognize the form:** This is a difference of squares because $$100 = 10^2$$ and $$121x^2 = (11x)^2$$.
3. **Recall the difference of squares formula:**
$$a^2 - b^2 = (a - b)(a + b)$$
4. **Apply the formula:**
$$100 - 121x^2 = (10)^2 - (11x)^2 = (10 - 11x)(10 + 11x)$$
5. **Final answer:**
$$\boxed{(10 - 11x)(10 + 11x)}$$