Question

Given that f (x) = 6x and g(x)= 3x-7 find: a. f(g(x)) b. g(f(x))

Answer 1

(a) 18x - 42 , (b) 18x - 7

Explanation:

(a)

to find f(g(x)) , substitute x = g(x) into f(x)

f(g(x))

= f(3x - 7)

= 6(3x - 7)

= 18x - 42

(b)

to find g(f(x)) , substitute x = f(x) into g(x)

g(f(x))

= g(6x)

= 3(6x) - 7

= 18x - 7

Answer 2

`\sf\\Solution:\\f(x)=6x\\g(x)=3x-7\\\\a)\ f(g(x))=f\{g(x)\}=f(3x-7)=6(3x-7)=18x-42\\b)\ g(f(x))=g\{f(x)\}=g(6x)=3(6x)-7=18x-7`