Lesson objective: Students understand that properties of operations hold for expressions.

Students bring prior knowledge of solving equations from 7.EE.A.1 and 7.EE.A.2. This prior knowledge is extended to solving linear equations in one variable as students explore linear equations in one variable and how operations can be applied to equations. A conceptual challenge students may encounter is understanding that equations can be solved in a variety of ways using operations.

The concept is developed through an examination of equations that illustrate how different operations can be applied in different ways.

This work helps students deepen their understanding of operations because they will apply properties of operations to a variety of equations.

Students engage in Mathematical Practice 2 (Reason abstractly and quantitatively) as they examine equations and their solutions.

**Key vocabulary:**

- infinitely many solutions
- one solution
- no solution
- identical