SOLUTION: A dehydrated patient needs a 6.4% saline IV. Unfortunately, the hospital only has bags of 6% and 8% saline solutions. How many liters of each of these solutions should be mixed to

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A dehydrated patient needs a 6.4% saline IV. Unfortunately, the hospital only has bags of 6% and 8% saline solutions. How many liters of each of these solutions should be mixed to      Log On


   

Question 354876: A dehydrated patient needs a 6.4% saline IV. Unfortunately, the hospital only has bags of 6% and 8% saline solutions. How many liters of each of these solutions should be mixed together to yield 1 liter of the desired concentration?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Let A be the amount of 6% solution, B the amount of 8% solution.
1.A%2BB=1
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6A%2B8B=6.8%281%29
2.3A%2B4B=3.4
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Multiply eq. 1 by -3 and add to eq. 2 to eliminate x.
-3A-3B%2B3A%2B4B=-3%2B3.4
highlight%28B=0.4%29 or 400 ml
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A%2B0.4=1
highlight%28A=0.6%29liter or 600ml