Answer:
B
Step-by-step explanation:
And arithmetic sequence is a sequence in which the difference between each of the numbers are constant.
It is not A, because the difference between 3 and 9 is positive 6, and the difference between 9 and 81 is positive 72.
It is not C, because the difference between 4 and 1 is -3, and the difference between 1 and 4 is positive 3.
It is not D, because the difference between 2 and -2 is -4, and the difference between -2 and 2 is positive 4.
And it is B because the numbers maintain a constant difference between each other, which is -3.
Let's start by visualising this concept.
Number of grains on square:
1 2 4 8 16 ...
We can see that it starts to form a geometric sequence, with the common ratio being 2.
For the first question, we simply want the fifteenth term, so we just use the nth term geometric form:


Thus, there are 16, 384 grains on the fifteenth square.
The second question begs the same process, only this time, it's a summation. Using our sum to n terms of geometric sequence, we get:



Thus, there are 32, 767 total grains on the first 15 squares, and you should be able to work the rest from here.
Three and eight hundredth seventy two thousandth
Answer:
f(-2) = -1
f(0) = -5
f(4) = -1
Step-by-step explanation:
The number inside of f( ) is telling you which equation to use to get the answer.
Example:
f(-2) since -2 is less than 0 you would use (x^2) - 5. So, ((-2)^2) - 5 = 4-5 = -1
f(0) since 0 is less than or equal to 0 you would use (x^2) - 5 again. So, ((0)^2) - 5 = 0-5 = -5
f(4) since 4 is grater than 3 you would use (2^(x-1)) - 9. So, (2^(4-1)) - 9 = -1
<u><em>The Graph, try to make it as straight as possible</em></u>
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