B is the answer to this question
        
             
        
        
        
^ means to the power of with nothing after it, it's miss-used. Solving without the ^ symbol it is -2xy with the ^ symbol it's irrational and cannot be solved.
        
             
        
        
        
A² = c² - b²
a² = 21² - 13 ²
a² = 441 - 169
a² = 272
a = √272 = 16.49242 ≈ 16.49
Answer : D ) 16.49
        
                    
             
        
        
        
Answer:
14/-11
Step-by-step explanation:
use the slope formula ( y2-y1/x2-x1)