If g(f(x))= 2x+1, f(x)= (1/4)x-1, then what does g(x) equal? The answer is supposed to be 8x+9. Can anyone explain to me clearly step by step how to do this? Thanks!

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- Jul 24th 2012, 01:45 PMwoahitzmeAlgebra 2 Composition of Functions?
If g(f(x))= 2x+1, f(x)= (1/4)x-1, then what does g(x) equal? The answer is supposed to be 8x+9. Can anyone explain to me clearly step by step how to do this? Thanks!

- Jul 24th 2012, 01:47 PMrichard1234Re: Algebra 2 Composition of Functions?
"Fit" the expression of f(x) into g(f(x)):

Therefore, . - Jul 24th 2012, 02:08 PMSorobanRe: Algebra 2 Composition of Functions?
Hello, woahitzme!

Quote:

. .

We are told that: .

Then: .

Assume that is a linear function: .

Then: .

We have: .

Equate coefficients: .

Hence: .

Therefore: .