The GCF is 3x so we have:-
3x(x^2 - 4x - 9)  <---- answer
        
             
        
        
        
Sin(angle) = Opposite /  hypotenuse
Sin(x) = 5/14
X = arcsin(5/14)
x = 20.9
X = 21 degrees.
 The answer is B.
 
        
             
        
        
        
0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5. 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5
        
             
        
        
        
8 - x < 5      |-8
-x < -3       |change the signs
x > 3
 
        
             
        
        
        
There are two possibilities of the formulas since I'm not exactly sure what this question is asking: 
Possibility 1: 8 = sqrt(x+7) in which the answer is 57. 
Possibility 2: 8 = sqrt(x) + 7, in which the answer is 1. 
Hope this helps! I'm sorry if I get it wrong.