I'm assuming you want me to make a formula for figuring your points after any given month assuming that you use the site at least once a month and you don't spend your points.
After one month, you will have your base 100 points plus an additional 10 points.
100 + 10 = 110
After two months, you will have gained an additional 10. 110 + 10 = 120
We can put this into a function, where P is your points, and m is the number of months you use the site.
P(x) = 100 + 10m
So after 500 months, you will have:
P(x) = 100 + 10(500) = 5100 points!
This is identical with: y = 100 + 10m
and
y = 10m + 100
So this can be graphed as a linear equation/function with a y-intercept of 100 and a slope of 10/1.
