In this section, students are shown equations that do not have a single solution. Students recognize that some equations have no solutions and others have infinitely many solutions, then find conditions that indicate how many solutions an equation has without completely solving it. This work also serves as a transition to examining systems of equations in which similar situations arise...

In this section, students focus on writing equivalent equations. They build a list of moves that can be used to write equivalent equations. Students begin by examining hanger diagrams as an intuitive way of understanding equivalence and the moves that maintain equivalence. These moves are described by labeling arrows that connect equivalent representations.

Then students reach the limits of hanger...

In this final section, students have the opportunity to apply their thinking from throughout the unit. As this is a short section followed by an End-of-Unit Assessment, there are no section goals or checkpoint questions.

In this section, students examine systems of linear equations and solve them by finding pairs of values that make both equations true. They begin by revisiting what it means when points are on or off a graphed line in relation to the equation represented by the line. Then, they recognize that a system of equations can be solved by finding...