State which of the following are equations (with a variable). Give reason for your answer. Identify the variable from the equations with a variable.
`7 - x = 5`

Answer

### Step-by-Step Solution:

1. **Identify the Expression**: The expression given is \( 7 - x = 5 \).

2. **Determine if it is an Equation**: An equation is defined as a mathematical statement that asserts the equality of two expressions, which is indicated by the equal sign (=). In this case, since there is an equal sign between the left-hand side (LHS) \( 7 - x \) and the right-hand side (RHS) \( 5 \), we can conclude that this is indeed an equation.

3. **Identify the Variable**: A variable is a symbol (often a letter) that represents an unknown value. In the expression \( 7 - x = 5 \), the letter \( x \) is present. Therefore, \( x \) is the variable in this equation.

4. **Provide Reasoning**: The reason we identify \( 7 - x = 5 \) as an equation is because it contains an equal sign, which shows that the two sides of the equation are equal. The presence of the letter \( x \) indicates that it is a variable, as it can take on different values.

### Final Answer:
- Yes, \( 7 - x = 5 \) is an equation with a variable.
- The variable in this equation is \( x \).

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