Answer:

Step-by-step explanation:
step 1
<u>Find the volume of the tank</u>
we know that
The volume of a cylinder (water tank) is equal to

in this problem we have 
 -----> the radius is half the diameter
 -----> the radius is half the diameter
 
 
substitute

step 2
Find the cost

 
        
             
        
        
        
I believe the percent decrease is 20%
as when you multiply 65.5 by 20%
it gives you 13.1
when you minus 13.1 from 65.50 
it gives you $52.4
        
             
        
        
        
Answer:
B 98
Step-by-step explanation:
4*7=28  times 3 = 84
3.5*4=14
84+14=98
Hope this helps! :)
 
        
                    
             
        
        
        
Step-by-step explanation:
By Descrates' Rule of Signs, 
x² + 99x + 127 changes sign 0 times.
Hence it has 0 positive roots.
Since the discriminant b² - 4ac is also positive, there are 2 real distinct roots.
Hence both the roots are negative. (B)