To be written in standard form, the exponents need to be in order from largest to smallest.
 The answer is: a. −3x^5 + 4x^3 + 10x^2 
 
        
             
        
        
        
Emma is now 24 years old then Ben would be 2E, or 48 years old.
<h3>What is a system of equations?</h3>
A system of equations is two or more equations that can be solved to get a unique solution. the power of the equation must be in one degree.
Let B and E be Ben's and Emma's current ages, respectively.
We have given that;
Ben's age is currently twice of his sister, Emma.
B = 2E 
and
8 years ago, Ben's age was 2 and a half times that of Emma's age
B-8 = 2.5(E-8)      
We can substitute the value of B from the first equation into the last one
B-8 = 2.5(E-8)
(2E)-8 = 2.5(E-8)
2E-8 = 2.5E- 20
-0.5E = -12
E = 24
Thus, Emma is now 24 years old then Ben would be 2E, or 48 years old.
Learn more about equations here;
brainly.com/question/10413253
#SPJ1
 
        
                    
             
        
        
        
You do not show us, so I can not answer this question.
        
             
        
        
        
Answer:
The answer to your question is:
Step-by-step explanation:
Data
1/2 hour free time
divide equally playing her favorite song and walking her dog
               Free time = F
               = 1/2 hour or 30 min
She divided equally her free time between walking her dog and palying her favorite song.
             30 min / 2 = 15 min
She has 15 min to walk her dog and 15 min to play her favorite song.
If she played her song 3 times, then:
               15 min / 3  = 5 min
Her favorite song lasts 5 min.