Answer:
21x²
Step-by-step explanation:
hopefully A is a typo
 
        
                    
             
        
        
        
<span>ΔABC, ΔDEF, and ΔGHI
</span>
I think all triangles are congruent. 2 sides and 1 angle of each triangle is has the same measure. Making these triangles congruent in SAS theorem.
        
                    
             
        
        
        
The function that the naval engineer uses related P (pressure) and d (depth of ocean). 
<em>Is there any restriction on the domain ( d: depth of the ocean)? Yes!</em>
The domain would be from 0 (at sea level or 0 depth) until the depth of the ocean (which is not infinite). Hence, we can write:

Choice D is the correct one.
ANSWER: D