Sounds as tho' you have a line going thru two points, A and B, but you have not shared those points. Please do so.
But we can assume that A:(a,b) and B:(c,d), find the slope and then write the equation of the line thru points A and B:
d - b
m = -----------
c - a
d - b
then the equation of the line is y-d = ----------- (x-c)
c - a
Please ensure that you are sharing all of the info given (e. g., the coordinates of the points A and B).