1. **Stating the problem:** A man buys a certain number of shirts for 2000 FRW. Each shirt costs some price, and if the price per shirt were 200 FRW less, he could buy 5 more shirts for the same total money. 2. **Define variables:** Let $x$ be the number of shirts bought. Let $p$ be the price per shirt. 3. **Form the first equation:** Total cost is $2000$, so $$x \times p = 2000$$ 4. **Form the second equation:** If each shirt cost $200$ FRW less, the price per shirt is $p - 200$. He could buy $x + 5$ shirts for the same total money, so $$(x + 5)(p - 200) = 2000$$ 5. **Express $p$ from the first equation:** $$p = \frac{2000}{x}$$ 6. **Substitute $p$ into the second equation:** $$(x + 5)\left(\frac{2000}{x} - 200\right) = 2000$$ 7. **Simplify the expression:** $$(x + 5)\left(\frac{2000 - 200x}{x}\right) = 2000$$ Multiply both sides by $x$: $$(x + 5)(2000 - 200x) = 2000x$$ Expand the left side: $$2000x + 10000 - 200x^2 - 1000x = 2000x$$ Simplify terms: $$2000x - 1000x + 10000 - 200x^2 = 2000x$$ $$1000x + 10000 - 200x^2 = 2000x$$ Bring all terms to one side: $$1000x + 10000 - 200x^2 - 2000x = 0$$ Simplify: $$-200x^2 - 1000x + 10000 = 0$$ Divide entire equation by $-200$: $$x^2 + 5x - 50 = 0$$ 8. **Name of the expression:** This is a quadratic equation formed from the problem conditions. **Final answers:** (a) The simplified expression is $$x^2 + 5x - 50 = 0$$ (b) This expression is called a quadratic equation.