Find the equation of a straight line that passes through the point(2,-1) and has x intercept of 4 units

Find the equation of a straight line that passes through the point(2,-1) and has x intercept of 4 units

Ok...if it has an x intercept of 4 units, it passes through the point (4,0)

Let's find the slope (m) between these points..we have

m = [0 - (-1)] / [4 - 2]  =  1/2

So, using one of the points (we can choose either, but (4,0) makes the problem easier) and the slope, we have

y - y₁   = (m)(x- x₁ )

y - 0 = (1/2) (x -4)

y = (1/2)x - 2

Checkimg this with the second point, we have

-1 = (1/2)(2) - 2

-1 = 1 - 2

-1 = -1

Looks like   y = (1/2)x - 2   is correct