So the formula is 
7*(1/3+1/5) = x
First find the common denominator of the fractions.  In this case the common denominator of 3 and 5 is 15 so we must convert them to 15ths.  To do that we divide 15 by the denominator and take that answer and multiply the numerator by it.
So for 1/3 we take 15/3(denominator) = 5 and multiply the numerator (1) by it
5 * 1 = 5 so 1/3 converts to 5/15
Do the same for 1/5 we take 15/5 = 3 and multiply the numerator (4) by it
3*4 = 12 so 4/5 converts to 12/15
Now we add 5/15 and 12/15 = 17/15 so we have our formula now to 
7*17/15
We make seven a fraction 7/1 and multiply across 7*17 = 119 and 15 * 1 = 15
We have 119/15 which when we divide and get 7 14/15 as your answer 
        
                    
             
        
        
        
The answer is c cause it is the only one that rotated
        
                    
             
        
        
        
Answer:
This is one of a variety of "subtraction solutions"--basically a different way to subtract by breaking numbers down into 10-digit chunks.  It's not especially helpful for small subtraction problems, but as math gets more complicated, this method will come in handy.
Step-by-step explanation:
Here's an example: Jim had a bag of 15 jelly beans.  He eats 8.  How many jelly beans does he have left?  <u>Take apart the number to make a 10. Then subtract.</u>
Here, you need to "take apart" the 8 to make your 15 jelly beans 10, then you subtract the remainder of 8 to get your solution.  In other words,
  --"take apart" 8 into 5 and 3 (because you're going to need a 5 to make 15 into 10).  15 minus 5 equals 10.  HOORAY!  You have your 10.  Now, subtract the remaining 3.  10 minus 3 equals 7.  Huzzah--your final answer!
On paper, the problem looks like this:
<u>15 - 8 (</u><u>5, 3</u><u>) = ?</u>
15 - 5 = 10
10 - 3 = 7
So...15 - 8 = 7
 
        
             
        
        
        
The answer is A. You use the inverse ln function on your calculator