First, ask somebody else like your teacher, also use your brain
        
             
        
        
        
I believe 10% because 390 and 39 are exactly the same numbers almost
        
                    
             
        
        
        
For this case we have to:
x: Represents the unknown number
y: Represents the exponent of base 10
So, considering a system of equations we have:

From the first equation we have:

Substituting in the second equation:

We choose the positive value:

So, the number is 0.4.
So:

Thus, the exponent is 5.
Answer:
Yara use 0.4 and
 
        
             
        
        
        
Answer: yes the ratios 1:9 and 5:45 are equivalent.
Step-by-step explanation:
1:9*5:5=5:45
U got any more math questions that I can answer? I’m really bored and I have to stay busy!