so in this case, we can make (x1, y1) = (2, 0.5) and (x2, y2) = (0.5, 1.25)
now plug these values into the formula n u get
(y - 0.5) / (x - 2) = (1.25 - 0.5) / (0.5 - 2)
plug the right side of the equation into the calculator (or you can do it by hand if you want) n u shud get (0.75) / (-1.5) = -0.5
now your equation becomes
(y - 0.5) / (x -2) = -0.5
multiply both sides of the equation by (x - 2) n you get
(x- 2)* (y - 0.5) / (x - 2) = -0.5* (x-2)
as you can see, the x - 2 cancels out on the left side of the equation n you get
y - 0.5 = -0.5 * (x-2)
now multiply out the right side of the equation (distributive property) (n be careful of the negative sign!!)
y - 0.5 = -0.5x + 1
add 0.5 to both sides of the equation
y - 0.5 + 0.5 = -0.5x + 1 + 0.5
n the 0.5's cancel out on the left side of the equation
n u get
y = -0.5x + 1.5
which is your answer
The formula above works for every problem of this type, so as long as you remember it you shud solve every problem of this type
Hope this helps!!