Question

The points (1, r) and (5, 1) lie on a line with slope 2. Find the missing coordinate r.

Answer 1

r=-7

Explanation:

Let (x1,y1) be (1,r)and (x2,y2) be (5,1)

Slope m=2

`slope = (rise)/(run) = (y2 - y1)/( x2 - x1 ) \\ = (1 - r)/(5 - 1) = 2 \\ 1 - r = 8 \\ r = - 7`