The answer is the first one.
Knowing that population density is like a rate, people per a given area, you would take the amount of people and divide by the area.
3.11E7/7.69E6 = 4.02 people per km squared.
Also the “E” is another way to write times 10 to a power and I recommend using that notation when plugging it into a calculator.
Option C:
is the product of the rational expression.
Explanation:
The given rational expression is 
We need to determine the product of the rational expression.
<u>Product of the rational expression:</u>
Let us multiply the rational expression to determine the product of the rational expression.
Thus, we have;

Let us use the identity
in the above expression.
Thus, we get;

Simplifying the terms, we get;

Thus, the product of the rational expression is 
Hence, Option C is the correct answer.
He gets <span>25 mpg </span>
<span>15 miles x 5 days = 75 miles </span>
<span>75 miles / 3 gallons = 25 mpg</span>
Let u = x², then we would have u² + 5u - 6 = 0
From here, we can factor it and get us (u-1)(u+6) = 0
So our solution for u is u = -6 or 1.
Now substitute u back to x².
x² = -6 or 1
x = ±√(-6) or ±√1
Since ±√(-6) is not real number, we ignore it.
Which leave us x = ±√1 = <span>±1
So our real solution is x = -1 or 1.</span>