Problem 3. The product of two numbers is 2250. If one of them is reduced by 6, and the other remains the same, then the new product is 1800. What are these numbers?
Solution. Let's denote the numbers with $a$ and $b$. We have:

$$
a \cdot b=2250 \text { and }(a-6) \cdot b=1800
$$

so:

$$
a \cdot b-6 \cdot b=1800 ; 2250-6 \cdot b=1800 ; \quad 6 \cdot b=2250-1800=450
$$

i.e. $b=450: 6=75$. Therefore, $a=2250: 75=30$.