, , , ,
This is a geometric sequence since there is a common ratio between each term. In this case, multiplying the previous term in the sequence by gives the next term. In other words, .
This is the form of a geometric sequence.
Substitute in the values of and .
Substitute in the value of to find the th term.
Subtract from .
Raise to the power of .
Multiply by .
Find the 7th Term 5 , 15 , 45 , 135 , 405