Answer:
B.
f(x) and g(x) are closed under subtraction because when subtracted, the result will be a polynomial.
Step-by-step explanation:

Assume m>=n WOLOG


Are also a polynomial in general, but maybe in a different degree
Closure under subtraction means, for all polynomials, under the operation of subtraction, it also belongs to polynomials
Volume is calculated by multiplying (3/4)pi by the radius cubed
None of those describe this function.
It's not a constant function, because it is not equal to a constant (something that isn't a variable)
It doesn't show direct variation, because it can't be represented in the form
y = kx.
It isn't an absolute value function because the absolute value isn't taken anywhere.
If it was an absolute value function it would look something like this:

It isn't a greatest integer function, because the greatest integer isn't taken anywhere.
If it was a greatest integer function it would look something like this:

Are you sure you typed that question right?
Answer:
6.5 = <em>h</em> + 2
<em>h</em> = 4.5
Step-by-step explanation:
We are given <em>h</em> and since she did 2 additional hours of work, we add the 2 hours. and since we are trying to find <em>h</em>, we set the equation equal to 6.5
P(at least 5 rolls until 1) = P(4 rolls are not 1) = 5/6 x 5/6 x 5/6 x 5/6 = 0.4823 (4sf)
Fewer than 7 rolls to get second 1 after first takes 3 rolls means second occurs on 4th, 5th or 6th roll
The probability of each of these is 1/6, 5/6 x 1/6 and 5/6 x 5/6 x 1/6 respectively.
P(second 1 on 4th, 5th or 6th roll) = 1/6 + 5/36 + 25/216 = 91/216 = 0.4213 (4sf)