you use those points and first find the sloope. so change in y over change in x
then once you find the slope. you plug in the points into y=mx+b ex: if you figured out that m=1 (the slope) then y= 1x +b..so then say you know that one point is 1,1 so 1=1(1)+b so then b =1//// hope this helps (brainliest answer greatly aprreciated (:)