The arithmetic sequence a; is defined by the formula:
aj = 15
di = Qi-1 - 7
Find the sum of the first 660 terms in the sequence.

Astore sells two types of radios. one type sells $87 and the other for $119. if 25 were sold and the sales were $2495, how many of the $87 radios were sold a) 5 b) 20 c) 15 d)10

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

Over the course of a month, a person's weight decreases. what type of relationship is this? a. positive relationship