Answer:

Step-by-step explanation:
We can write the following system of equations:

Adding both equations together, we isolate  and get:
 and get:

Plugging  in any of the equations, we can solve for
 in any of the equations, we can solve for  :
:

Verify that the solution pair  works
 works 
Therefore, the two numbers are  .
.
 
        
             
        
        
        
Use the law of cosines to find a: 

So to use the given numbers you get: 

Which would come out to equal about 35.94
so a=35.9
 
        
        
        
Subtract 2b by both sides which gets -b+4=-5 then subtract 4 by both sides so you get -b=-9 and divide -1 by both sides so that b=9
        
                    
             
        
        
        
Problem 2
Part (a)
The 3D shape formed when rotating around the y axis forms a pencil tip
The shape formed when rotating around the x axis is a truncated cone turned on its side.
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Part (b)
Check out the two diagrams below. 
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Problem 3
Answer: Choice A and Choice C
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Explanation:
Think of stacks of coins. Let's say we had 2 stacks of 10 quarters each. The quarters are identical, so they must produce identical volumes. Those sub-volumes then add up to the same volume for each stack. Now imagine one stack is perfectly aligned and the other stack is a bit crooked. Has the volume changed for the crooked stack? No, it hasn't. We're still dealing with the same amount of coins and they yield the same volume. 
For more information, check out Cavalieri's Principle. 
With all that in mind, this leads us to choice C. If the bases are the same, and so are the heights, then we must be dealing with the same volumes.
On the other hand, if one base is wider (while the heights are still equal) then the wider based block is going to have more volume. This leads us to choice A.