In this section, parallel lines are explored. A graphing calculator is needed.

How can parallel lines be identified by looking at a table?

Look at the following table.

Fill in the blanks by using the table on the right of the graph. Click on the blank to check your answer.

• There are several ways to determine if there is a solution from a table, look for a Interactive button. Assistance may be required. __________ pattern , calculate the vertical Interactive button. Assistance may be required. __________ distance , plot Interactive button. Assistance may be required. __________ points and find the Interactive button. Assistance may be required. __________ slopes of the lines.
• The vertical Interactive button. Assistance may be required. __________ distance is the same between the points; therefore the lines are Interactive button. Assistance may be required. __________ parallel .

• The slopes of the lines are Interactive button. Assistance may be required. __________ the same , if the slopes are Interactive button. Assistance may be required. __________ the same there is not one unique solution. The lines are either coinciding or Interactive button. Assistance may be required. __________ parallel .
• When the points are plotted they appear to be the Interactive button. Assistance may be required. __________ same distance apart, showing the lines are Interactive button. Assistance may be required. __________ parallel .

1. Put the following two functions in your graphing calculator: y = 3x + 4 and y = 3x − 7
2. The slopes of the lines are Interactive button. Assistance may be required. __________ the same.
3. Press graph, the lines look Interactive button. Assistance may be required. __________ parallel.
4. Presses 2nd Graph to display a table of values, the vertical differences are Interactive button. Assistance may be required. __________ the same.
5. The lines are Interactive button. Assistance may be required. __________ parallel.