Answer:
x = amount of pure acid to be added = 6.67ml
Step-by-step explanation:
George wishes to increase the percent of acid in 50ml of a 15% acid solution in water to 25% acid, how much pure acid must you add?
let 
x = amount of pure acid to be added
15% of 50 + x = 25% of 50 + x
(0.15 * 50) + x = 0.25(50 + x)
7.5 + x = 12.5 + 0.25x
Collect like terms
x - 0.25x = 12.5 - 7.5
0.75x = 5
x = 5/0.75
x = 6.6666666666666
Approximately,
x = 6.67
x = amount of pure acid to be added = 6.67ml
 
        
             
        
        
        
.03*.03=.009 .009*.03=.000027 so the answer is .000027
        
             
        
        
        
45                                        90 
 /  \                                       /  \
5  9                                     45  2
   /  \                                   /  \
  3   3                                5   9 
 5x3x3                                   / \  
                                          3    3
                                        2x5x3x3
        
             
        
        
        
The correct answer is (-3,1)