How do I tell whether the point is below or above the line?

Question

640.Show that P = (3.2,6.3) is not on the line 4x−y = 7. Explain how you can tell whether

P is above or below the line.

Answer 1

By plugging in x=3.2 into the function and solving for y:

4x-y=7

4(3.2)-y=7

12.8-y=7

12.8-7=y

5.8=y

Since 5.8<6.3, then (3.2,6.3) lies above the line.

Hope this helped!

Answer 2

Plug the value x = 3.2 into the equation and solve for the y-value:

1. If the y-value = 6.3 then the point (3.2,6.3) lies on the line
2. If the y-value > 6.3, then the point (3.2,6.3) lies below the line
3. If the y-value < 6.3, then the point (3.2,6.3) lies above the line