60a^5 is the answer to your question
        
             
        
        
        
Answer:
120
Step-by-step explanation:
 
        
             
        
        
        
X = -1/4
Move the 1 to the other side then divide by 4 on both sides
        
                    
             
        
        
        
Answer:
17.37
Step-by-step explanation:
y varies inversely as the square root of x
Mathematically:
y = k.root x
We first find k here 
To find k, we were made to know that y is 21 and x = 361
k = y/root.x
k = 21/root. 361
k = 21/19
now what is y when x = 247
From y = k.root x
y = 21/19 * root 247
y= 21/19 * 15.72
y = 17.37