5. the numbers are being multiplied by 4 each time, so the geometric sequence would be
an= 1/2(4) ^(n-1)
6. the numbers are being multiplied by 1/4 each time, so the geometric sequence would be
an= 32(1/4)^(n-1)
an in the formula is what ever term in the sequence.
32 or 1/2 is the a which is the first term in the sequence.
4 or 1/4 is the r in the sequence because it is the common ratio so what the equation was multiplied by to get the next term.
(n-1) is because when you are using this equation to solve for whatever term (an) you must subtract the first number in the sequence to get an accurate number
an you can input whatever number when trying to solve.