The sum of the 1st nine terms of an arithmetic series is 216. The 1st,3rd and the 7th terms of series form the 1st three terms of a geometric series. Find the 1st term and the constant difference of the arithmetic series ?
Find the 10th term of a nonconstant arithmetic sequence whose 1st term is 3 with the 1st, 4th, and 13th term forming a geometric sequence. I've tried doing it differently everytime, but I always come to a dead end..
The 1st,5th,13th term of an arithmetic sequence are the first 3 terms of geometric sequence with a common ratio of 2. If the 21st term of the arithmetic sequence is 72, calculate the sum of the first 10 terms of the geometric
The third and seventh terms of an arithmetic sequence are 10 and 20. 1) What is the value of the 1st term? 2) What is the value of the 9th term? 3) What is the equation to find the nth term in the sequence? HELP!! PLEASE!!
The 1st, 5th and 13th terms of an arithmetic sequence are the first three terms of a geometric sequence with a common ratio 2. If the 21st term of the arithmetic sequence is 72, calculate the sum of the first 10 terms of the
In an arithmetic progression, the 5th term is six times the 1st term and the sum of the first six terms is 99. Find the 1st term and the common difference. Attempt at solution: U5 = 6(U1) 99 = 3(2[U1] + 2d)
I have a Q that im trying to solve: it says: the 1st , 2nd, and 3rd term of a geo. sequence is the same as the 1st, 7th and 9th terms of an arith. sequence.: I have to find the common ratio. So i know: a+8d = a(r^2) (1) a+6d = ar