Answer:
Option B is correct.
Step-by-step explanation:
The distance formula used is:
We need to find distance between origin and other point (3,-4,5)
Origin is: (0,0,0)
x₁ = 0, y₁ = 0, z₁ =0 and x₂= 3, y₂= -4 and z₂ = 5
Putting values in the distance formula we get:
The Distance from the origin to the point (3, −4, 5) is 7 units.
Option B is correct.
Answer: 119,616
You may have to erase the comma when inputting the answer.
=======================================================
Explanation:
The author sells 21,000 books in the first month.
Then they sell 21,000*(1-0.12) = 21,000*(0.88) = 18,480 in the second month.
Then they sell 18,480*(1-0.12) = 18,480*(0.88) = 16,262.4 = 16,262 in the third month.
And so on. These values follow a geometric sequence with first term a = 21,000 and common ratio r = 0.88
We can think of the 0.88 as 88% of the original value (since losing 12%, we keep the remaining 88%)
-------------
Use the formula below to sum the first 9 terms of the geometric sequence
Plug in a = 21000 and r = 0.88
The author sold about 119,616 books over the course of the first nine months.