Answer:
B
Step-by-step explanation:
Let x be the number of packages of paper towels.
Each package of paper towels costs $2.79.
Then x packages of paper towels cost $2.79x.
Hence, a function f(x) is

Practically, you can buy 0 packages, 1 package, 2 packages and so on, only whole numbers of packages, so practical domain is all whole numbers.
Answer:
The swimming pool will contain approx
of water.
Step-by-step explanation:
Given the swimming pool is in a cylindrical shape.
And the dimensions are
diameter with a height of 
Also, 
First, we will find the volume of the swimming pool.
The swimming pool is in cylindrical shape.
So, the volume would be 
The height
is given as
To calculate radius
we will divide the diameter by two.
The radius of the cylinder would be 
Plug these values in the formula we get,

Now, it is given 
So, 
The swimming pool will contain approx
of water.
Let's represent the two numbers by x and y. Then xy=60. The smaller number here is x=y-7.
Then (y-7)y=60, or y^2 - 7y - 60 = 0. Use the quadratic formula to (1) determine whether y has real values and (2) to determine those values if they are real:
discriminant = b^2 - 4ac; here the discriminant is (-7)^2 - 4(1)(-60) = 191. Because the discriminant is positive, this equation has two real, unequal roots, which are
-(-7) + sqrt(191)
y = -------------------------
-2(1)
and
-(-7) - sqrt(191)
y = ------------------------- = 3.41 (approximately)
-2(1)
Unfortunately, this doesn't make sense, since the LCM of two numbers is generally an integer.
Try thinking this way: If the LCM is 60, then xy = 60. What would happen if x=5 and y=12? Is xy = 60? Yes. Is 5 seven less than 12? Yes.