SOLUTION: let f(x)= 3xsquared - 1 and g(x) = 2x + 5 find f(g(-1)) and g(f(-1))

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Question 10312: let f(x)= 3xsquared - 1 and g(x) = 2x + 5
find f(g(-1)) and g(f(-1))

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
First find f(-1) and g(-1).
If f%28x%29+=+3x%5E2 then f%28-1%29+=+3%28-1%29%5E2 = 3
If g%28x%29+=+2x%2B5 then g%28-1%29+=+2%28-1%29%2B5 = 3
So, f%28g%28-1%29%29+=+f%283%29 = 3%283%29%5E2+=+3%289%29 = 27
and g%28f%28-1%29%29+=+g%283%29 = 2%283%29%2B5+=+6%2B5 = 11