D.
(-4v*3v) + (-4v*-5) + (3v*7) + (7*-5)
-12v^2 + 20v + 21v -35
-12v^2 + 41v -35
The length and breadth(width) of the pool are

Let

From the question, we can build the following relationships

subtracting to eliminate
(we do not even need it!)

we can also build another relationship from the question. Since the area of the strip equals the area of the pool:

We have two unknowns,
and
. Eliminate 

If we solve the quadratic equation for
, we get

and

The length and breadth(width) of the pool are

Learn more about area here: brainly.com/question/1447350
Answer:49/4
Step-by-step explanation: