SOLUTION: a group of biologists studied the nutritional effects on rats that were fed a diet containing 10% protein. the protein was made up of yeast and corn flour. by changing the percen

Algebra ->  Equations -> SOLUTION: a group of biologists studied the nutritional effects on rats that were fed a diet containing 10% protein. the protein was made up of yeast and corn flour. by changing the percen      Log On


   

Question 184129: a group of biologists studied the nutritional effects on rats that were fed a diet containing 10% protein. the protein was made up of yeast and corn flour. by changing the percentage P ( expressed as a decimal ) of yeast in the protein mix, the group estimated that the average weight gain g (in grams) of a rat over a period of time was given by
g= -200p^2 + 200p + 20
what percentage of yeast gave an average weight gain of 60 grams ?
I need the answer with steps please, thanks
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
g= -200p^2 + 200p + 20
what percentage of yeast gave an average weight gain of 60 grams ?
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60 = -200p^2 + 200p + 20
-200p^2 + 200p - 40 = 0
-5p^2 + 5p - 1 = 0
p = [-5 +- sqrt(25 - 4*-5*-1)]/-10
p = [-5 +- sqrt(5)]/-10
p = [-5 - sqrt(5)]/-10
p = 0.7236 = 72.36%
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Cheers,
Stan H.