S = n(a+1) for a

please answer asap

Asequence {an} is defined recursively, with a1 = 1, a2 = 2 and, for n > 2, an = an-1 an-2 . find the term a241

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Ineed with angles and the measure of them i have abc a is 65 and b is (3x-10) and c is (2x) find the value of x