Answer:
-5.457875
Step-by-step explanation:
 
        
             
        
        
        
7x300=7x 3 hundres because in 300 hundreds there is 3 hundreds.I know that didnt make sense.so basically just look at the front number number its 3 so 3 hundreds but if your working with thousands and the front number is 5 its 5 thousands.I hope this was helpful.
        
             
        
        
        
As an opportunity to respond to people who might disagree with your claim. 
 
        
                    
             
        
        
        
First, we get the area of each tile: (100 cm = 1m)
.20 m* .15 m = 0.03m^2
Then, we solve for the total area of the wall:
5m*3m= 15m^2
Then we divide 
15/0.03 = 500 tiles
        
             
        
        
        
The correct answer is 42x^4-24x^3+12x^2