Answer:
Option A.
Step-by-step explanation:
Area of a square is
.... (1)
where, x is side length.
The length of each side of his square plot is decreasing at the constant rate of 2 feet/year.

It is given that bob currently owns 250,000 square feet of land.
Fist find the length of each side.


Taking square root on both sides.

Differentiate with respect to t.

Substitute x=500 and
in the above equation.


Farmer bob is losing 2,000 square feet of land per year.
Therefore, the correct option is A.
The first option :
Multiply the first equation by 8 and the second equation by 2
would not result in the elimination of the variables in this system
Answer: 
Step-by-step explanation:
You know that the triangle ABC and the triangle DEF are similar.
Therefore, if the lenght of AC is 12 centimeters and the lenght of DF is 10 centimeters, then you can find the ratio as following:

Then, the calculte the length of EF, you must multiply the lenght BC of the triangle ABC by the ratio obtained above.
Therefore, the lenght EF is the following:

If the ratio of the dimensions is 4:7 and the shorter dimension is 10ft, we know that the 10ft corresponds to the 4 in this scenario. We can set up the equation as follows:

You have to multiply by 2.5 to get from 4 to 10. And since we want to make sure we are maintaining the ratio, we have to multiply the denominator, 7, by 2.5 as well.

This means your shorter side has a length of 10ft and your longer side has a length of 17.5ft.
AREA
The formula for the area of a rectangle is: 
So we can plug our dimensions into the formula: 
So 175 is our area. But we can't forget about units! Since this is area and we multiplied our units together, our units would be squared. That means our answer is <u>175 square feet</u>.
PERIMETER
The formula for the perimeter of a rectangle is: 
We can plug our dimensions into the formula: 
So 55 is our perimeter. Of course, we can't forget about our units. Because this is perimeter, we only added our units together, so they don't change. That means our answer is <u>55 feet</u>.
50 cents beacuse in 1970 it cost 50 cents in 1980 it cost 1.00