How do you write an equation from a word problem when they give you two coordinate plots?

Answer 1

y-y1=m(x-x1)

x1 = the x value in the first coordinate
y1 = the y value in the first coordinate

m (slope, or rise over run) = (y2-y1) / (x2-x1)

Answer 2

For more info, Google: Point Slope Form