Someone me i'm struggling right now

If you look at the number of stars in each box you get:

2, 4, 6, 8

So this is an arithmetic sequence with a common difference with each term being 2 greater than the previous term.

Any arithmetic sequence can be expressed as:

a(n)=a+d(n-1), a=initial term, d=common difference, n=term number

In this case a=2 and d=2 so 

a(n)=2+2(n-1)  which can be simplified

a(n)=2+2n-2

a(n)=2n

So the fifth term in the sequence is:

a(5)=2(5)

a(5)=10