ANSWER
The correct answer is

EXPLANATION
The mapping for reflection across the x-axis is given by

Given

. We can let

we can write the ordered pair

or

as the ordered pair of the preimage of

.
The image function will have the ordered pair

or

.
That is, we negate all the y-coordinates.
Therefore

.
There are a couple of ways you can solve this. You can write it out like
(K-3)(K-3)(K-3)(K-3)(K-3)(K-3)(K-3)
And pretty much use the foil method
Or you can use the binomial theorem (google it if you dont know)
The solution should be:
(K^7) - 21(k^6) + 189(k^5) - 945(k^4) + 2835(k^3) - 5103(k^2) + 5103k - 2187
A conservative vector field

has curl

. In this case,

so the vector field is not conservative.
Answer:
a) P = 0.039
b) The expected number of days is 10 days.
Step-by-step explanation:
The most appropiate distribution to use in this case is the geometric distribution, in order to calculate the probability of a success after k failure trials.
The probability of success, as each of the 10 products are assumed to have fair probabilities, is:

Then, the probability that our product is not selected any given day is:

a) The probability that exactly this product is selected exactly 10 days from now is the probability that is not selected (probbility q) for the next 9 days and selected (probability p) at the 10th day:

b) The expected number of days is calculated as:
