Answer:
The answer is 3! I believe.
Step-by-step explanation:
 
        
                    
             
        
        
        
By using my brain I can figure it out.
        
                    
             
        
        
        
I think you mean
sqrt x + 5 = sqrt (x+45)
if you plug in x = 4,
left side = sqrt 4 + 5 = 2+ 5 = 7
right side = sqrt (4+45) = sqrt 49 = 7
so the answer is x = 4 :)
        
                    
             
        
        
        
129/43x100=300
129 is 43% of 300