Video6: Given 2 Equations

For this example, it tells you it gives you two equations. So Y equals negative two over 5 X plus 9. And Y equals 5 over two X plus 8. And they want to know if these two lines are parallel or perpendicular. The first thing I look for is to see if the slope, which is a number in front of the X are the same. They're not the same. This has a negative two. This has a 5. So we know it's not parallel in order to be perpendicular to the 5 has to be at the top, the two has to be at the bottom, and they have to have different signs. I do see the 5 at the top, the two at the bottom. This is a negative slope. This is a positive slope, so that means that these two lines are perpendicular.