SOLUTION: solve using a system of equations. I know you have to do something like x+y+x+y=, but then I get so confused. A 40% saline solution is to be mixed with a 60% saline solution

Question 408464: solve using a system of equations.
I know you have to do something like x+y+x+y=, but then I get so confused.
A 40% saline solution is to be mixed with a 60% saline solution to obtain 8 liters of a 55% solution. How many liters of each solution should be used?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
In words:
(liters of salt in 40% solution + liters of salt in 60% solution)/(liters of solution) = 55%
Let = liters of 40% solution needed
Let = liters of 60% solution needed
---------------------------------
given:
= salt in 40% solution
= salt in 60% solution
------------------------
(1)
(2)
This is 2 equations and 2 unknowns, so it's solvable
----------------------
(1)
(1)
(1)
(1)
and, also,
(2)
(2)
Subtract (2) from (1)
(1)
(2)

and, since
(2)

2 liters of 40% solution and 6 liters of 60% solution are needed
check answer:
(1)
(1)

OK

RELATED QUESTIONS
I must solve the system of equations by graphing. x-y=-2 x+y=12 I cancelled out the (answered by Alan3354)

hi! i was wondering if you could help me with this question (at a basketball game, a team (answered by ReadingBoosters)

I know that I need three equations to solve the system, but it seems like I don't have... (answered by venugopalramana)

I do not know how to solve system equations using substitions with fractions. Do i... (answered by ptaylor)

The system of linear equations has a unique solution. Find the solution using Gaussian... (answered by AnlytcPhil)

I really need your help, I am sort of confused. We didn't go over an example like this... (answered by Mathtut)

When finding a solution of system of equations, for a conic intersection, how do you know (answered by lwsshak3)

I need help with using the elimination method to solve 5/x + 2/y = 0 6/x + 4/y =... (answered by checkley77)

Hi, I am trying to solve this system of equations: 2x+y=8 (answered by mananth)