John does 5 pushups on the first day of a 30day month and th

John does 5 pushups on the first day of a 30-day month, and then increases the number of pushups by 3 pushups a day. How many pushups has he done by the end of the month? Find the sum of the first n terms of the geometric sequence for the values of a_1 and r. n = 4, a_1 = 168, r = 3.4 Find the indicated term for the geometric sequence with the first term a_1 and common ratio r. Find a_2 when a_1 = 1728, r = 1/4 Write an expression for the general or nth term, a_n, of the arithmetic sequence. -6, -1, 4, 9, ...

Solution

5) n = 4

a1 = 168

r = 3.4

Sn = a1 ( 1- r^n ) / (1-r )

Sn = 168 ( 1 - 3.4^n ) / (1 - 3.4 )

Sn = 168 ( 1 - 3.4^n ) / 2.4