If you get the answers right you will get brainliest and get a : -)

5.   3, 12, 48, 192, 768, ...

You can find the 15th term by using the formula , where  is the first term of the sequence, r is the common ratio, and n is the number of the term you want to find.

  Plug in your information (the common ration is x4)
  Simplify the exponent
  Multiply


The 15th term of the sequence is 805306368.

6.   200, 40, 8, 1.6, ...
Using guess and check, I found that the pattern here is ÷5, ÷5, ÷5, .... That can also be written as ×, ×, ×, ... When you are multiplying the terms of a sequence, that is a geometric sequence.