so we see that it is x and y
x is number of candy bars
y is cost
so the numbers are
100,165 and 600,196
first we want to make it into slope inercept form
y=mx+b m=slope, b=y inercept
slope= (y1-y2)/(x1-x2)=(165-196)/(100-600)=-31/-500=31/500
slope is 31/500
y=31/500x+b
subsitute
165=31/500(100)+b
165=31/5+b
subtract b from both sides
165-b=31/5
multiply both sides by 5
5(165-b)=31
325-5b=31
add 5 b to both sides
325=31+5b
subtaract 31 from both sides
294=5b
divide both sides by 5
48 and 4/5=b=48.8
y=31/500x+48.8