Answer:
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
In the world of exponents, 4 is the number being raised by the exponent, which is 2. 
Let's answer the first question:
If the base is 4, what is the value if the exponent is 2?
- The base is 4 and the exponent is 2.  We would multiply 4 two times.

So, it would be 16.
Let's answer the second question:
What if the exponent is -2?
<u>This is the rule for negative exponents:</u>
 
 
Using this rule, we can solve  .
.

So, our answer for the 2nd question is 1/16.
 
        
             
        
        
        
It equals 3/16 because I first multiplied the first to fractions together and I know that negative times a positive is negative so we would get a negative and I also multiplied the 2 to get -9/40 and then multiplied -5/6  to -9/40 to get the answer of 3/16!
 
        
             
        
        
        
Answer:
A 20
Step-by-step explanation:
Given 
Phone Battery Life (hours)
A 20
B 25
C 10
D 18
8.45% of the battery life of each mobile phone is used in a day by a typical user
Calculating Hours of battery life in a day for each mobile
A 20
Battery life for A =  hours
hours
B 25
Battery life for B =  hours
hours
C 10
Battery life for C =  hours
hours
D 18
Battery life for D =  hours
hours
Therefor Mobile phone A 20  uses a total of 1.69 hours of battery life in a day