Answer:
as shown in the attached file. 
Step-by-step explanation:
The detailed, step by step explanation and application of integral with appropriate substitution to get the expression for the time of extinction is as shown in the attachment. 
 
        
             
        
        
        
Answer:
x^2 and 5x
3x and 15
Step-by-step explanation:
 
        
             
        
        
        
Answer:
B=62, a=3.7, C=7.9
Step-by-step explanation:
 
        
             
        
        
        
The answer is 49.89
hope this helped:)