Answer: 
Step-by-step explanation:
1. You know that:
- The roped-off area whose width is represented with <em>x,</em> it is created around a rectangular museum.
- The dimensions of the rectangular museum are: 30 ft by 10 ft.
- The combined area of the display and the roped-off area is 800 ft².
2. The area of the rectangular museum can be calculated with:

Where
is the lenght and
is the width.
You have that the lenght and the width in feet are:

3. Let's call
the width of the roped-off area. Then, the combined area is:

Where



4. Substitute values and simplify. Then:


I think 71 is B
and 72 is D.
Answer:
-5/2 is the reciprocal of -2/5, but the opposite would just be 5/2.
Step-by-step explanation:
Answer:
C =131.88 meters
Step-by-step explanation:
The circumference of a circle is given by
C = 2*pi*r
where r is the radius
C = 2 * pi * 21
C = 42 pi
If we approximate pi by 3.14
C = 42(3.14)
C =131.88 meters