1. What does y=mx mean? Where does it come from?

2. In this lesson you will learn to derive the equation y=mx by using similar triangles.

3. Let’s Review For any line, the ratio of rise to run is constant. We call this ratio the slope of the line. 4 6 6 9

4. Let’s Review A Common Mistake Be careful!

5. Let’s Review Core Lesson (0, 0) 2 3 (x, y) y x

6. Let’s Review Core Lesson Slope: m (0, 0) m 1 (x, y) y x y = mx

7. Let’s Review Core Lesson Any point (x,y) on a line through the origin with slope m will satisfy y=mx. y=mx is the equation of a line through the origin with slope m.

8. In this lesson you have learned to derive the equation y=mx by using similar triangles.

9. Let’s Review Guided Practice Use similar triangles to demonstrate that the equation of a line through the origin with slope 3 is y=3x.

10. Let’s Review Extension Activities

11. Let’s Review Extension Activities A line through the origin passes through (5,6). What is the line’s equation?

12. Let’s Review Quick Quiz