a = 4, b = -21, c = -18
to keep from getting "mixed up", evaluate the discriminant first ...
b<sup>2</sup> - 4ac = (-21)<sup>2</sup> - 4(4)(-18) = 729
sqrt(729) = 27 
x = (21 +/- 27)/8
x = -3/4, x = 6
since the discriminant is a perfect square, the original quadratic will factor ...
4x<sup>2</sup> - 21x - 18 = 0 
(4x + 3)(x - 6) = 0
x = -3/4, x = 6
 
        
                    
             
        
        
        
Answer:
B
Step-by-step explanation:
Please see the answer in the picture attached below.
" From Step 1: We find that Angle N1 equals to 75 gradius => Answers A and C wrong. Answers B and D are left.
" From Step 4: We find that Angle N2 equals to 129 gradius => Answer B is true.
You don't need to find the exact value of the angle N3 in oder to choose the right answers from A,B,C,D.
Hope this answer can help you. Have a nice day!
 
        
             
        
        
        
Pretty much anything over 50 is 100
        
             
        
        
        
Answer
I think its C which is 112