Question #5e39e

2 Answers
Oct 10, 2017

15x+3515x+35

Explanation:

I'm assuming you mean (g\circ f)(gf).

f(x)=5x+9,\qquad\qquad g(x)=3x+8

(g\circ f)(x)\impliesg(f(x))

So, just plug in f(x) for the x in g(x):

g(x)=3 color(red)(x)+8

(gcirc f)(x)=3( color(red)(5x+9))+8

Now, just solve using simple algebra:

15x+27+8

15x+35

\therefore\qquad (g\circ f)(x)=15x+35

Oct 10, 2017

(g@f)(x)=15x+35

Explanation:

(g@f)(x)=g(f(x))

In other words: replace x with f(x) in the function g(x)

(g@f)(x)=3(f(x))+8

So:

(g@f)(x)=3(5x+9)+8

(g@f)(x)=15x+27+8

(g@f)(x)=15x+35