1. **State the problem:** We want to understand how to express and work with the expression \( \frac{12}{x} \). 2. **Formula and explanation:** The expression \( \frac{12}{x} \) means 12 divided by \( x \), where \( x \) is a variable and cannot be zero because division by zero is undefined. 3. **Important rule:** \( x \neq 0 \) because division by zero is not allowed. 4. **Simplification or evaluation:** If you have a specific value for \( x \), substitute it into the expression to find the value. For example, if \( x=3 \), then \( \frac{12}{3} = 4 \). 5. **Additional note:** You can also write \( \frac{12}{x} \) as \( 12x^{-1} \) using exponent notation. This is the basic understanding of the expression \( \frac{12}{x} \).