Lesson 20

In the associated Algebra 1 lesson, students rewrite expressions with the goal of showing that for any equal intervals of the independent variable, an exponential function always changes by an equal factor and a linear function always changes by an equal difference. In this lesson, students practice using the properties they will need to rewrite expressions, including exponent properties and applying the distributive property with a negative coefficient. When students repeatedly perform calculations and then generalize, they are expressing regularity in repeated reasoning (MP8). If students decide to use technology to efficiently evaluate the same function for different input values, they are using appropriate tools strategically (MP5).