If Monica walks
1km...........................15min
?km............................60min
60/15=4
Monica walks 4km in 60 min(1H)
1km=1,000m
4km=4,000m in 1 hour
Answer:

And solving for the radius we got:

And replacing the data given we got:

And this value converted to meters is 
Step-by-step explanation:
For this case we know the population size
and we also know the population density 
We can assume that the area is a circle. We also know that the formula for the population density is given by:

Where P represent the number of people and A the area. Since we are assuming a circle then the area is given by:

With X the radius of the circle
And then the populationd density become:

And solving for the radius we got:

And replacing the data given we got:

And this value converted to meters is 
Answer:
(2x-9)(2x+9)
Step-by-step explanation:
This is a difference of squares because it can be written as (2x)^2-9^2
The formula for factoring a difference of squares is a^2-b^2=(a-b)(a+b)
So replace a with 2x and b with 9 giving us
4x^2-81=(2x-9)(2x+9)
And I don’t want to you know what to you
7x³ = 28x is our equation. We want its solutions.
When you have x and different powers, set the whole thing equal to zero.
7x³ = 28x
7x³ - 28x = 0
Now notice there's a common x in both terms. Let's factor it out.
x (7x² - 28) = 0
As 7 is a factor of 7 and 28, it too can be factored out.
x (7) (x² - 4) = 0
We can further factor x² - 4. We want a pair of numbers that multiply to 4 and whose sum is zero. The pairs are 1 and 4, 2 and 2. If we add 2 and -2 we get zero.
x (7) (x - 2) (x + 2) = 0
Now we use the Zero Product Property - if some product multiplies to zero, so do its pieces.
x = 0 -----> so x = 0
7 = 0 -----> no solution
x - 2 = 0 ----> so x = 2 after adding 2 to both sides
x + 2 = 0 ---> so = x - 2 after subtracting 2 to both sides
Thus the solutions are x = 0, x = 2, x = -2.