Unit 4, Lesson 23# The Defining Equation of a Line

EngageNY 45 min(s)

Students know that two equations in the form of ax + by = c graph as the same line under special conditions. Following the Exploratory Challenge is a Discussion that presents a theorem about the defining equation of a line and then a proof of the theorem. The Discussion can end with the theorem, and in place of the proof, students can complete Exercises. Whether the teacher chooses to discuss the proof or have students complete Exercises, it is important that students understand that two equations that are written differently can be the same, and their graph is the same line.