Determine if the sequence 9,18,36 is geometric or arithmetic. write an explicit formula

9                             18                        36

                             9 * 2                     18 * 2

so notice, to get the next term, we simply multiply the "current" one by 2, namely is a geometric sequence, with a "common ratio" of 2, and we know the first term's value is 9.

The answer is 26 to 1