y = mx + b
y = value of x term
x = term number
m = rate of change = 8
b = solved for

Now let's solve for b by plugging in values for x and y
3 = 8*1 + b
3 = 8 + b
b = -5

Let's test it with the third term:
m is still 8
b is still -5
y is 19
x is 3

y = mx + b
19 = 8*3 - 5
19 = 24 - 5
19 = 19
Correct! We got the right formula!

So the nth term is 8n-5!!!
=> 100th = 8.100 - 5 = 795