Find the sum of the first 11 terms of the geometric sequence 4, -4, 4, .. 4

The sum of two consecutive terms in the arithmetic sequence 3, 5, 7, 9, ... is 204; find these two terms. The first consecutive term of the arithmetic sequence is The second consecutive term of the arithmetic sequence is

6. Find the 25th term of the sequence -1, 3, 9, ... -

How many terms of the arithmetic sequence 3,5,7... must be added together to get 899?

Determine the sum of the first five terms of the geometric sequence where a =3 and r=2. The sum is

Determine the sum of the first four terms of the geometric sequence where a = 3 and r= -1. The sum is