SOLUTION: A chemist has a beaker of a 3% acid solution and a beaker of a 7% acid solution.He needs to make 75mL of a 4% acid solution.With the information given,write a system of linear equa

Question 539670: A chemist has a beaker of a 3% acid solution and a beaker of a 7% acid solution.He needs to make 75mL of a 4% acid solution.With the information given,write a system of linear equations and solve the system.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A chemist has a beaker of a 3% acid solution and a beaker of a 7% acid solution.He needs to make 75mL of a 4% acid solution.
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Quantity: t + s = 75
Acid:::: 3t +7s = 4*75
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Multiply thru the Quantity equation by 3 to get:
3t + 3s = 75
3t + 7s = 4*75
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Subtract and solve for "s":
4s = 3*75
s = 56.25 oz (amt. of 7% solution needed)
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Solve for "t":
t + 56.25 = 75
t = 18.75 oz (amt. of 3% solution needed)
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Cheers,
Stan H.
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