Answer:
all right triangles are 90 degrees and in total there is 9x so you divide 90 by 9 to get x=10 A
 
        
             
        
        
        
The sequence is 
740, 707.60,675.20,642.80,...
Here first term is 740, and common difference, d is 

Now we use the formula of nth term, which is

Substituting the values of a,n and d, we will get

Correct option is the second option .
 
        
             
        
        
        
Step-by-step explanation:
the answer is In photo above 
 
        
             
        
        
        
We cannot determine the cost of the tiles from the given information, so the question cannot be answered.