Answer:
C
Step-by-step explanation:
Because of all the variables in the side lengths, we don't have enough information to use side-angle-side similarity. 
We do have two angles of one triangle congruent to two corresponding angles of the other triangle, so we can use angle-angle similarity.
Sides AE and AD are corresponding sides. Sides AC and AB are corresponding.
Answer: C
 
        
             
        
        
        
So the question is asking to covert the said formula by making the a as the solution or the ask of the said equation, well in that matter, I would say, base on my own conversion and further computation about the said equation, the value of a is (y+z)/(x+w).  I hope this would help 
        
             
        
        
        
B. (Not sure)
(5+A)
———
(a-1)
        
             
        
        
        
9514 1404 393
Answer:
   x^2 +4x -21
Step-by-step explanation:
Substitute the given expressions and simplify.
   f(x) + g(x)
   = (x^2 +3x -28) +(x +7)
   = x^2 +(3+1)x +(-28 +7)
   = x^2 +4x -21
 
        
             
        
        
        
Option #2 
11.56 is rounded to 12 because the 6 rounds the 5 to a 6. 11.6 then rounds to 12.