Need help ! Please explain how to answer this question please?

Question

anonymous · Answer

Rober believes that the rise in flu cases is due to shifting weather patterns: Predict the number of cases in year 5 ?

anonymous · Answer

@SolomonZelman

solomonzelman · Answer

it goes up twice each time (just like in your previous question)

anonymous · Answer

sorry man these questions make me go beyond what they're suppose to lol i keep thinking it's going to be some crazy algebra reference

solomonzelman · Answer

it;s alright.

a personal tip -

when you look at this type of questions (let's take this very question for example)
you can see that to get the second term you have to either add 489 or multiply times 2.

which one works to get from 2nd term to the 3rd?
adding 489 doesn't so "multiplying times 2" is then the pattern.