Answer:
810
Step-by-step explanation:

 
        
             
        
        
        
Answer:
103 ft. 
Step-by-step explanation:
 
        
                    
             
        
        
        
Option a is true and others are false
        
             
        
        
        
Answer:
2. 
3. 
Step-by-step explanation:
We add like terms together to simplify
2.  3x²-4x²= -x²     -2x+5x= 3x  6+9= 15  all equal to -x²+3x+15
3.  2x²-3x²= -x²      6x-7x= -x    8+1=9      all equal to -x²-x+9