It's a similar triangle so the ratios of corresponding sides should be equal which means
BC/EF = AB/DE
21/14 = AB/10
AB = 21/14 * 10 = 15 cm
        
                    
             
        
        
        
Step-by-step explanation:
None is better they have the same score in percentage.
 
        
                    
             
        
        
        
This is pretty simple once you get used to this
First set it equal to the original and the negative one
(>_) is the bigger and equal to part 
4x+5>_45 or 4x+5>_-45
Then solve for x for both 
4x>_40. 4x>_-50
X>_10 X>_-25/2
        
             
        
        
        
X= -193 over 30
Or X= -6.43 recurring
        
                    
             
        
        
        
Answer:
The correct answer is:
r + 0.50 = 10.25: Subtract .50 from both sides. The answer is $9.75.
This is because Juan got a $0.50 raise which means that his new rate will be $0.50 more than his original rate (r).