Expert: Lynn Houston - 12/4/2008

Question
a line passes through (1,-5) and (-3,7). write the equation in point slope form then rewrite in slope intercept form..please help.

Answer
slope is y2-y1/x2-x1 so the slope of the line through the two coordinates is

7-(-5)/-3-1 = -4.

Slope intercept is y = mx + b where m is the slope and b is the y intercept.  You have the slope now and you have two points (ie x & y), so plug them into the eq and solve for b.

-5 = -4(1) + b
-1 = b

so the slope intercept form is y = -4x -1