8 litres (amount of 20% solution needed) and 7 litres for (amount of 50% solution needed)
<u>Step-by-step explanation:</u>
Let consider ‘x’ for 20% acid solution and (15 – x) for 50% acid solution. And so, the equation would be as below,
                           20% in x + 50% in (15 – x) = 15 litres of 34%
Convert percentage values, we get
                               0.20(x) + 0.50 (15 – x) = 15 (0.34)
                               0.20 x + 7.5 – 0.50 x = 5.1
                               -0.3 x + 7.5 = 5.1
                               0.3 x = 7.5 – 5.1
                               0.3 x = 2.4

Apply ‘x = 8’ value in (15 – x) we get,
                          15 – 8 = 7 litres
The value of 7 litres for (amount of 50% solution needed)
 
        
             
        
        
        
Answer:
1 A, 2c, 3A, 
4 P= 2(6x-1) + 2(2)   P=12x +2
Step-by-step explanation:
 
        
             
        
        
        
<em>x = 1</em>
<em><u>Here is why:</u></em>

Add x to both sides.

Add 5 to both sides.

Divide.
x = 1
 
        
                    
             
        
        
        
 
Prime Factors of 504: 2, 3, 7 
 23 × 32 × 71 where 2, 3, 7 are prime.
 
        
             
        
        
        
222.118 estimated is 222.1 and 236.103 estimated is 236.1 so subtracted equals 14.0