Video by Julie Harland http://yourmathgal.com This is part 19 of a series of videos about graphing lines. This video covers how to find the equations of lines if you know the slope and a point. Goes over the point-slope formula.<br />For more great math videos visit: www.youtube.com/user/videosbyjulieharland/videos<br />Aligned to Common Core State Standard: 8.EE.6
Graphing Lines Part 19
Use similar triangles to explain why the slope 𝑚 is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation 𝑦 = 𝑚𝑥 for a line through the origin and the equation 𝑦 = 𝑚𝑥 + 𝑏 for a line intercepting the vertical axis at 𝑏.