1. The problem is to understand and simplify the expression $15x^2y$. 2. This expression is a product of a constant coefficient 15 and variables $x^2$ and $y$. 3. The term $x^2$ means $x$ is squared, or multiplied by itself: $x \times x$. 4. The variable $y$ is multiplied directly by $15x^2$. 5. Since there are no like terms to combine or further simplification, the expression is already in its simplest form. 6. Therefore, the simplified expression is $15x^2y$.