Answer:
at what?
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
The nth term of a geometric progression is
= a₁
where a₁ is the first term and r the common ratio
Given a₅ = 162 and a₈ = 4374 , then
a₁
= 162 → (1)
a₁
= 4374 → (2)
Divide (2) by (1)
= 
r³ = 27
r = ![\sqrt[3]{27}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B27%7D)
= 3
Substitute r = 3 into (1) and solve for a₁
a₁
= 162
81a₁ = 162
a₁ = 
= 2
Then
a₂ = a₁ × 3 = 2 × 3 = 6
a₃ = a₂ × 3 = 6 × 3 = 18
The first 3 terms are 2, 6, 18
(ii)
The sum to n terms of a geometric progression is
= 
, then
= 
= 
= 59049 - 1
= 59048
So, let's see... It is easy to notice that for 3 out of the 4 numbers, there is a relationship between the x and the y coordinate of the number; for 3+i, -2i, -2-4i we have that the real part is larger by 2 from the imaginary part. Thus, the points are on the same line in the imaginary plane; they satisfy x=y+2 or Re{z}=Im{z}+2. However, 2-4i does not satisfy this equation since 2 is not equal to -4+2. Hence, this point does not belong to the line that the other 3 points define.
Basically you know that the 2 wholes from both sides cancel out.
Set up the equation, 5/8 = 3/12 + 3/x
3/x = 5/8 - 3/12
Set them to have a common denominator, 3/x = 15/24 - 6/24
3/x = 9/24
Simplify 9/24 and you will get 3/8
3/x = 3/8
Obviously this means x = 8
