Your answer should be 17 inches. 
2.5 + 2.5 = 5 7 + 3 = 10 + 5 + 2 = 17.
I hope this helps answer your question. Have a great day
 
        
             
        
        
        
Are there any other details as to what the numbers are? otherwise there are six possibilities for this 
12+54=66
66=6(_+_)
11=(_+_)
1) 0, 11
2) 1, 10
3) 2, 9
4) 3, 8
5) 4, 7
6) 5, 6
        
                    
             
        
        
        
Domain is all real Numbers
Range is all numbers over 0 - (0,
∞
)
        
                    
             
        
        
        
Your answer is 3/7 because you have to go 5-5=0 and 5/7-2/7=3/7 so it is 3/7
        
                    
             
        
        
        
205.2 square feet
Convert 90% to a decimal. You get .9 Multiply 228 by .9 to find what 90% of 228 is. You should get 205.2.