ANSWER
 = 9
= 9 

Step-by-step explanation
The volume of a rectangular prism is given by the formula, 
 =
= 
 x
 x 
 x
 x 

We substitute the dimensions to obtain, 
 = 6 x 3 x 12
= 6 x 3 x 12 

The volume of the rectangular pyramid is, 
 =
= 
 x 6 x 12 x
 x 6 x 12 x 
 
 

Equating the two values gives, 
 x 6 x 12 x
 x 6 x 12 x 
 = 6 x 3 x 12
 = 6 x 3 x 12
We divide through by 6×12 to get, 
 = 3
 = 3
We solve for x to obtain, 
 = 3 x 3
 = 3 x 3 
 = 9
 = 9 

Hope this helps! Happy Monday!