Question

The first, third and ninth terms of a linear sequence are the first three terms of an exponential sequence. If the seventh term of the linear sequence is 14 calculate the twentieth term of the linear sequence and the sum of the first twelve terms of the exponential sequence

Answer 1

since GP's have a common ratio,
r = (a+2d)/a = (a+8d)/(a+2d)
a+6d = 14
So, solve for a and d, and then find
a+19d
S12 = a(r^12 - 1)/(r-1)

Answer 2

The 7th term of an AP is 4 and its Common difference is -4. What is its first term
1 point
16
20
24
28

Answer 3

I want this question solved in fully understandable, but where they wrote 14 is 4 so the 14 is error

Answer 4

To be solved