The answer is the first page, first graph
X=4
First find the solution to (x+1) ft. I chose to guess the answer as 4 and it worked (you’ll have to guess). I then plugged 4 into the other equation 2x. It became 2•4. Solving give the side length of 8 ft. Then you have to check to make sure they both have the same area. To do this just solve the equations.
First rectangle- 4•4= 16 ft area
Second rectangle- 2•8 = 16 ft area
( I’m really sorry if this is confusing)
The answer would be 43.96 for 3.5 hours because for each hour it's 12.56
Solution
For this case we can use the following formula:

Where:
P= 400800 = present value
A= future value
r= 0.055 interest rate
n= 4, number of times that the interest is compund in a year (quarterly)
t= 4 years
Replacing we got:

then the interest would be: