SOLUTION: A doctor prescribes an oitment that is 2% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How much of each should she use to make a 1-ounce tube

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Question 154725This question is from textbook college algebra ninth edition
: A doctor prescribes an oitment that is 2% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How much of each should she use to make a 1-ounce tube This question is from textbook college algebra ninth edition

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A doctor prescribes an ointment that is 2% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How much of each should she use to make a
1-ounce tube.
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Let amt. of 1% be x: amt. of active ingredient = (0.01x) oz.
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Amt of 5% is "1-x" ; amt. of active ingredient = 0.05(1-x) = (0.05 - 0.05x) oz.
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Amt of 2% is 1 oz; amt. of active ingredient = 0.02*1 = 0.02 oz
EQUATION:
acive + active = active
Active Ingredient equation: 0.01x + 0.05 - 0.05x = 0.02*1
-0.04x = -0.03
x = 0.75 oz (amt. of 1% ointment in the mix)
1-0.75 = 0.25 oz (amt. of 5% ointment in the mix)
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Cheers,
Stan H.