Answer:
Ques 16)
We have to simplify the expression:

Ques 17)

Ques 18)
Let the blank space be denoted by the quantity 'x'.

Ques 19)
Let the missing quantity be denoted by 'x'.

 
        
             
        
        
        
Well, for any prism, it is the lateral area + the area of two ends.  
        
             
        
        
        
I don't see the answers, but it would most likely be 59 + x.
        
             
        
        
        
C and E that is the answer
        
             
        
        
        
C=300+1200x-100x. Find x if the total cost is 3,000
3,000 = 300 + 1200x -100x
3000 = 300 + 1100x
2700 = 1100x
2700÷1100=x
x=27/11
x = 2 5/11
Round to 3