Answer:
S12=855735
Step-by-step explanation:
if the 3rd term is 45 then,
formula: Sn=ar^n-1
S12=5*3^12-1
S12=5*3^11
S12=5*177147
S12=855735
Answer:
120
Step-by-step explanation:
We know that 36 is 30% of total items
So our equation would be 36/? = 30/100
From there we cross multiply so 36x100 = 3600
From there, we divide 3600 by 100
Therefore, your answer is 120
Answer:
Option E
Step-by-step explanation:
Explicit formula of a geometric sequence is,

Here,
First term
common ratio
number of terms
If,
and 
Common ratio of the sequence 


By substituting these values in the formula,

Therefore, Option E is the answer.
Basically you're solving for both variables here.
I prefer elimination method so that is what I used.
I started off by multiplying each equation in order to get one of the variables at the same value so it would be possible to cancel it out.
Multiplying the first equation by 3 gave me,
12x + 15y = 69
Then I multiplied the second equation by 4,
-12x + 28y = -56
As you can see, it's not possible to cancel out the x variable.
12x + 15y = 69
+(-12x + 28y = -56)
_____________
13y = 13
Then just solve for y which gives you -1.
After you have one variable solved simply insert it into one of the original equations to find the other variable.
4x + 5(-1) = 23
4x - 5 = 23
4x = 28
x = 7.
And there you have it! Hope this helped!
Answer:
81
Step-by-step explanation: