You need 20 liters of 20% acid solution. you have jugs of 10% solution and 25% solution. how many liters of each should you combine to get the needed solution?

6.(6) and 13.(3) liters.

Step-by-step explanation (this way is not the shortest one):

1. the basic rule is: the mas/volume of pure substance after and before combination is the same.

2. There is 4 liters of pure substance in 20*0.2 acid solution (20*0.2=4);

3. if 'x' is the volume of pure substance in 10%-solution; and if 'y' is the volume of pure substance in 20%-solution, then their sum of volumes is 4. It means, x+y=4 - this is the 1-st equation for system.

4. the volume of 10%-solution is x/0.1=10x; the volume of 20%-solution is y/0.25=4y; their sum is 20 litres. It means, 10x+4y=20 - this is the 2-d equation of the system.

5. to calculate the volumes of the pure substance:

6. to calculate the volume of 10%-solution: 2/3 *10=20/3≈6.(6) litres;

to calculate the volume of 25%-solution: 10/3 *4=40/3≈13.(3) litres.

hope it you

step-by-step explanation:

sin(7pi/6 - pi/3)  

= sin(7pi/6 - 2pi/6)  

= sin(5pi/6)  

= sin(pi - pi/6)  

= sin(pi/6)  

= 1/2  

sin 7pi/6 - sin pi/3  

= sin (pi + pi/6) - sin pi/3  

= -sin pi/6 - sin pi/3  

= -1/2 - sqrt(3)/2  

= -(1+sqrt(3))2

x = 17

step-by-step explanation:

1st step: isolate x.

24 - 3x = -27

-24         -24

-3x   =   -51

2nd step: divide.

-3x     =   -51

  3             3

  x       =     17

hope this