Sum of n terms of a geometric series is
Sn = a1 (r^n-1)/(r-1)
a1 = 1st term = 4
r = common ratio = 12/4 = 3
so, the sum is
Sn = 4 (3^n-1)/(3-1) = 2(3^n-1)
Answer:
D.
7.68 × 108
Step-by-step explanation:
World population in 2013 was about 7.125 billion
In 2003 , it was about 6.357 billion
Increase = 2013 population- 2003 population
That’s 7.125 billion - 6.357 billion = 0.768 billion
A billion has 9 zeros. When you move The point one place to the right , it reduces the number of zeros by one. you now have
7.68 x 10^8
Answer: (c - 3) / 2 = x
Step-by-step explanation:
If c represents the cookies, then you remove 3 because she ate 3 of the cookies. Since half of the remainder of the cookies were given to her friend, you must divide the product of c - 3, by 2. The reason for the parenthesis is so that it overrules PEMDAS, as parenthesis goes before division.
Answer: a(n) = 5 - 3n
the sequence has:
a1 = 2
a2 = -1
a3 = -7
.........
we can see that: a2 - a1 = a3 - a2 = -3
=> the sequence is a arithmetic sequence
=> the distance between the numbers is d = -3
because this sequence is a arithmetic sequence
=> a(n) = a1 + (n - 1)d = 2 + (n - 1).(-3) = 5 - 3n
Step-by-step explanation:
Answer:
It's 2
Step-by-step explanation:
X is 2 because if you multiply two by two you get 4
