Answer:
Addition.
Step-by-step explanation:
Multiplication is a faster way to do repeated addition. 
For example, lets say you would add 10 fifteen's together. Addition would make it: 
15 + 15 + 15 + 15 + 15 + 15 + 15 + 15 + 15 + 15
 = 30 + 30 + 30 + 30 + 30
    = 60 + 60 + 30
       = 120 + 30
           = 150
However, when multiplying: 
15 x 10 = 150
As you can tell, multiplication makes it so there are less steps, and is less time consuming.
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Answer:
Simon takes approximately 13.76 hours to complete the job alone.
Step-by-step explanation:
We are given the following in the question:
Kamila can do a job in 26 hours  
So, part of work done by Kamila in 1 hour = 

Simon and Kamila working together can do the same job in 9 hours
.
So, (Simon and Kamila)'s 1 hour work = 

So, Simon's 1 hour work =

So, 
Simon can do  part of work in hour = 1
 part of work in hour = 1
Time taken by Simon to complete the job alone =

Thus, Simon takes approximately 13.76 hours to complete the job alone.
 
        
             
        
        
        
Answer: I can't answer this
Step-by-step explanation:
 
        
             
        
        
        
Answer:
22/10 or 2 and 1/5
Step-by-step explanation:
To find the perimeter, add all sides together. Since it's a rectangle, the other sides are the same measurement as the ones given. Add 3/10, 3/10, 4/5, and 4/5 together. To do this, find a common denominator. The lowest common denominator is 10 so multiply the 4/5 by 2/2 to get the denominator to be 10. Now, add 3/10, 3/10, 8/10, and 8/10. It adds up to 22/10 but if you don't want an improper fraction, simplify it to 2 and 1/5.
 
        
             
        
        
        
If I understand the question, you have to get n alone. in this case, you have to subtract 7 from both sides, resulting in n (is less than) -10