Answer:
y= -0.2x+14
Step-by-step explanation:
you have to do y2-y1/x2-x1 of any two coordinates or points so you could do 9.8-10.2/21-19 then you get -0.4/2 and that equals -0.2 so -0.2 is now ur slope or M. Next you pick any coordinate like (19,10.2) and you plug that into ur y=mx+b to find the b since you have found the m already from y2-y1/x2-x1. You could do 10.2= 19(-0.2)+b once you do the algebra to solve this you get 14 as your b or y intercept