1. The problem is to identify the variables in a given mathematical expression or equation. 2. Variables are symbols that represent unknown or changeable values in mathematics, often letters like $x$, $y$, or $z$. 3. To identify variables, look for letters or symbols that are not fixed numbers or constants. 4. For example, in the expression $3x + 5 = 11$, the variable is $x$ because it represents an unknown value. 5. If you provide a specific expression or equation, I can help identify the variables present in it.