All you need to find is a and d
he first thing to do is use the formulas correctly, and use all the data given:
S3 = 3/2 (2a + 2d) = 165
T2 = a+d = 11a
So, d = 10a
3/2 (2a+20a) = 165
22a = 110
a = 5
d = 50
The sequence starts 5 55 105
The sum of 3 consecutive terms of an arithmetic sequence is 165. The second of these terms is 11 times the first. Find the 3 terms
From what I gathered:
S(3) = 165 t(2)= 11(t1)
The given formulas are:
Sn= n/2[2a+(n-1)d] and tn=a+(n-1)d
I have no idea how to continue.
1 answer