Answer:
The answer to your question is:
Step-by-step explanation:
Equations are equalities with one or more variables, in their structure is the equality sign (=).
1.- It's an equation because there is one variable and the sign of equality.
2.- It's an equation, there is a variable (x).
3.- It's an expression because it does not have the equality sign although it has a variable.
4.- It's an expression because it does not have the equality sign although it has a variable.
