A cylinder has  a cross section of a circle as well as the sphere.
        
             
        
        
        
Answer:
x = 3 + √6 ; x = 3 - √6 ;  ;
 ;  
Step-by-step explanation:
Relation given in the question:
 (x² − 6x +3)(2x² − 4x − 7) = 0
Now,
for the above relation to be true the  following condition must be followed:
Either  (x² − 6x +3) = 0 ............(1)
or
(2x² − 4x − 7) = 0 ..........(2)
now considering the equation (1)
(x² − 6x +3) = 0
the roots can be found out as:

for the equation ax² + bx + c = 0
thus,
the roots are

or

or
 and, x =
 and, x = 
or
 and, x =
 and, x = 
or
x = 3 + √6 and x = 3 - √6
similarly for (2x² − 4x − 7) = 0.
we have
the roots are

or

or
 and, x =
 and, x = 
or
 and, x =
 and, x = 
or
 and, x =
 and, x = 
or
 and,
 and, 
Hence, the possible roots are
x = 3 + √6 ; x = 3 - √6 ;  ;
 ; 
 
        
             
        
        
        
Answer: 304
Step-by-step explanation: first you multiply 9, 3, and 12 which equals 324. Then you subtract 20 from 324 and you get 304.