I believe A and B are the ones. As for explaining? hmm. I would honestly say that any number to the right of a number is a tenth of the place above it. But then again, it's optional to explain ;P
LFX=AZQ
XLF=QAZ
FXL=ZQA
XFL=QZA
You multiply 55.25 by 0.18. You get 9.945 and then you add it to 55.25. You should get 65.195. Round it to $65.20. That's your answer.
A full circle in radians is 2π, and in degrees it's 360°. I want to convert the 72° to radians:
72° in radians = 72/360 * 2π = 2/5π
The circumference of a full circle is the number of radians times the radius. (ie., 2πr), so the JK part of the circle is:
5* 2/5π simplifies to 2π
1. Note that

2. Then the equation
can be rewritten

3. Solve it:

Answer: x=6