Find the value of r so that the line passes through the pair of points has the given slope. (-1,r), (1,-4), m=-5

Question

I have no idea how to slove this problem out, ive beem working on it for an hour or 2 please help me out. So how can i figure this out step by step.

Answer 1

Slope is rise/run, which in this case is (r - (-4))/(-1 - 1) = (r + 4)/(-2). Since m = -5,

 

-5 = (r + 4)/(-2)

 

Multiplying both sides by -2 yields

 

10 = r + 4

 

Subtracting 4 from both sides, we obtain

 

6 = r.