Answer:
O is the center of the circle with radius IE(=ID=EF)
Step-by-step explanation:
Join all 3 points D, E, F, forming the triangle DEF.
Let the midpoint of EF be M and the midpoint of ED be N. (first picture)
Join point I to E, D and F.
Since IN is both an altitude and median to triangle EID, then triangle EID is an isosceles triangle, and IE=ID
similarly, we see that IE=IF.
conclusion: IE=ID=EF.
 
        
                    
             
        
        
        
(s÷t) - r is the correct expression.
        
             
        
        
        
Answer:
4 tiles are added to each figure in the tile pattern. 
 
        
             
        
        
        
Answer:
138.80
Step-by-step explanation:
I took 149.99 times 15% then times that by the tax rate to get your final answer. 
 
        
             
        
        
        
Answer:
x=(8/3, infinity)
Step-by-step explanation:
-3x+8<15-3x+8
-3x+8<-3x+23
8<23 
15-3x+8<15
23-3x<15
-3x<-8
x>8/3
Therefore, x=(8/3, infinity)