Find the slope of the lines. Are the graphs of the two lines parallel our perpendicular? Explain how you can use the slope of the two lines to tell if they are parallel. Then explain how you can use the slope of the two lines to tellI'd they are perpendicular.

y = 3/7x + 11

7x + 3y = 13

You know that two lines are parallel if they have the same slope and you can tell if two line are perpendicular if they have slopes that are opposite reciprocals, for example, 4's opposite reciprocal is - 1/4. The two lines would be perpendicular because if you solve the second equation you get y=-7/3+13/3 and - 7/3 is the opposite reciprocal of 3/7.