Answer:
Base = x = 18ft
Height = x - 4 = 14ft
Step-by-step explanation:
The formula for the area of A the triangle is given by the following equation:
1) A = (base * heigth)/(2)
From this problem, we know that
base = x and that the height is 4ft less than the base, so height = base - 4 = x - 4.
We also know that the area is 126ft², so A = 126 ft². Now we can replace these informations in equation 1).
126 = (x(x-4))/2
x² - 4x = 252
x² -4x - 252 = 0
The roots of this equation are x = 18 or x = -14. But we know that a triangle cannot have negative dimensions, so we use x = 18.
The base is x, so base = 18ft.
Height is 4ft less than the base, so height equals 18-4 = 14ft

Taking

gives

, so that the integral becomes





When

, we have


and from here we can substitute

to proceed from here.
Quick note: When we set

, we are implicitly enforcing

just so that the substitution can be undone later via

. But note that over this domain, we automatically guarantee that

, so the absolute value bars can be dropped immediately.
Answer:
6 ketchup / 1 mustard
Step-by-step explanation:
3 ketchup = 0.5 mustard
6 ketchup per 1 mustard
<span>The rectangle with the largest area with a given perimeter will be a square - so the sides will be equal. So we need to find length of side, L, such that 4*L=168.
L = 168/4
L=42.
So the dimensions of the rectangle that maximizes the area with a perimiter of 168 feet are: 42 feet by 24 feet.</span>
Answer:

The world population at the beginning of 2019 will be of 7.45 billion people.
Step-by-step explanation:
The world population can be modeled by the following equation.

In which Q(t) is the population in t years after 1980, in billions, Q(0) is the initial population and r is the growth rate.
The world population at the beginning of 1980 was 4.5 billion. Assuming that the population continued to grow at the rate of approximately 1.3%/year.
This means that 
So


What will the world population be at the beginning of 2019 ?
2019 - 1980 = 39. So this is Q(39).


The world population at the beginning of 2019 will be of 7.45 billion people.