SOLUTION: f(x) = -13x^2 - 13x + 14 and g(x) = -13x - 11 find g(g(3)) AND f(x) = 15x + 12 and g(x) = -10x^2 + 15 find f(g(-2)) I can't figure these out for the life of me

Algebra ->  Functions -> SOLUTION: f(x) = -13x^2 - 13x + 14 and g(x) = -13x - 11 find g(g(3)) AND f(x) = 15x + 12 and g(x) = -10x^2 + 15 find f(g(-2)) I can't figure these out for the life of me      Log On


   

Question 1089013: f(x) = -13x^2 - 13x + 14 and g(x) = -13x - 11
find g(g(3))
AND
f(x) = 15x + 12 and g(x) = -10x^2 + 15
find f(g(-2))
I can't figure these out for the life of me :(( please help
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29+=+-13x%5E2+-+13x+%2B+14 and g%28x%29+=+-13x+-+11
you have g%28g%28x%29%29-> since you are given f%28x%29 and g%28x%29; so, I believe you need to find highlight%28f%28g%283%29%29%29

to find f%28highlight%28g%283%29%29%29, you can first evaluate highlight%28g%283%29%29 and it will be value of x for f%28x%29
highlight%28g%283%29%29=-13%2A3+-+11=-39-11=-50
then, go back to f%28highlight%28g%283%29%29%29 plug in -50 for highlight%28g%283%29%29; so, you will have:
f%28highlight%28-50%29%29=-13%28-50%29%5E2+-+13%28-50%29+%2B+14
f%28highlight%28-50%29%29=-13%282500%29+%2B+650+%2B+14
f%28highlight%28-50%29%29=-32500+%2B+650+%2B+14
f%28highlight%28-50%29%29=-31836

AND
f%28x%29+=+15x+%2B+12 and g%28x%29+=+-10x%5E2+%2B+15
find+f%28g%28-2%29%29
g%28-2%29+=+-10%28-2%29%5E2+%2B+15
g%28-2%29+=+-10%2A4+%2B+15
g%28-2%29+=+-40+%2B+15
g%28-2%29+=+-25
then +f%28g%28-2%29%29=f%28-25%29
+f%28g%28-2%29%29=f%28-25%29=15%28-25%29+%2B+12
+f%28g%28-2%29%29=f%28-25%29=-375+%2B+12
+f%28g%28-2%29%29=f%28-25%29=-363