SOLUTION: Ok I have this really complicated problem that i don't know howto Solve can you please help me: Use composition of functions to prove that it does matter what order you use these

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: Ok I have this really complicated problem that i don't know howto Solve can you please help me: Use composition of functions to prove that it does matter what order you use these       Log On


   

Question 190415: Ok I have this really complicated problem that i don't know howto Solve can you please help me:
Use composition of functions to prove that it does matter what order you use these discounts at the store to get the greatest toal discount. The coupons are for $25 and 40% discount on your total purchase price.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Use composition of functions to prove that it does matter what order you use these discounts at the store to get the greatest toal discount. The coupons are for $25 and 40% discount on your total purchase price.
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Let f(x) = x-25
Let g(x) = 0.75x
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f[g(x)] = f[0.75x] = 0.75x-25
g[f(x)] = g[x-25] = = 0.75(x-25) = 0.75x-18.75
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Evaluate if x = $100
f[g(100)] = 0.75*100-25 = $50
g[f(100)] = 0.75*100-18.75 = $56.25
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Cheers,
Stan H.