Lines 1 and 2 can be manipulated by moving the corresponding sliders. Click and drag the sliders.

- Move the sliders until you make the two lines parallel. What do you notice about the equations of the lines?
- Change the equation of Line 1 to
*y*= 2*x*+ 1. Make a prediction: what does the equation of Line 2 need to be in order for the lines to be parallel. Test that prediction. - How many different equations can you make for Line 2 that will be parallel to Line 1?

Athena Matherly, November 7, 2006, Created with GeoGebra

Please direct questions and comments to HCPS Mathematics Specialist Henrico County Public Schools, 2009