If f(x) = x2 + x and g(x) = x - 8, what is f(g(x))?

Question

how di find the answer to my question

Answer 1

f(x) = x^2 + x

g(x) = x-8

 

f(g(x)) simply means that we replace whatever we see for x [in f(x)]  with  g(x).

 

This means that we have g(x)^2 + g(x)

 

but g(x) = x-8.

 

(x-8)^2 + (x-8)

 

FOIL :  (x-8)(x-8) =  x^2 - 16x + 64

 

x^2 -16x + 64   +  x - 8

 

x^2 -15x + 56   <---- ANSWER

 

 

Hope this helps!

Answer 2

f(g(x))

= f(x-8)

= (x-8)^2 + (x-8)

= x^2 - 15x + 56 <==Answer