1. The problem involves simplifying and understanding the expression $x^2 - 100$ and the related expressions given. 2. First, recognize that $x^2 - 100$ is a difference of squares, which can be factored using the formula: $$a^2 - b^2 = (a - b)(a + b)$$ where $a = x$ and $b = 10$. 3. Applying the formula: $$x^2 - 100 = (x - 10)(x + 10)$$ This factorization is useful for solving equations or simplifying expressions. 4. The variable $c$ is given as 100, which matches the constant term in the expression. 5. The expression $(c \pm su)$ is unclear without further context, so we focus on the main expression. 6. The expression $2x^2 - 249 + 10$ simplifies by combining like terms: $$2x^2 - 249 + 10 = 2x^2 - 239$$ 7. This is a quadratic expression in standard form. 8. Since no specific equation or value to solve for is given, the main takeaway is the factorization of $x^2 - 100$ and simplification of $2x^2 - 239$. Final answers: - Factorization: $$x^2 - 100 = (x - 10)(x + 10)$$ - Simplified expression: $$2x^2 - 239$$