How do I solve

Question

"Find the equation (in terms of x) of the line through the points (-1,1) and (1,3)"?

Answer 1

Given, Points (-1, 1) and (1,3)

Two points form of line equation : y - y1  =  [(y2 - y1) / (x2 - x1)] X (x - x1)

Let (x1, y1) = (-1, 1) and (x2, y2) = (1, 3)

Substitute (x1, y1) = (-1, 1) and (x2, y2) = (1, 3) in Two - Points Form

y - 1  =  [(3 - 1) / (1 -(-1))] X [x - (-1)]

y - 1  =  [2/(1+1)] X (x + 1)

y - 1  =  [2/(1+1)] X (x + 1)

y - 1  =  (2 / 2) X (x + 1)

y - 1  =  (x + 1)

(y - 1) - (x + 1)  =  0

y - 1 - x -1  =  0

y - x - 2  =  0

y - x  =  2.

Answer :

The Line Equation is y - x  =  2.