Question

If f(x) = 2x+7 and g(x) = -3x+5, what is f(g(4))?

Answer 1

Answer is -7

Plug 4 in for g(x) and solve to get x=-7.Plug x=-7 in for f(x).

Answer 2

-7

Explanation:

So we have the two functions:

`f(x)=2x+7\text{ and } g(x)=-3x+5`

And we want to find f(g(4)).

So, find g(4) first:

`g(x)=-3x+5\\g(4)=-3(4)+5`

Multiply:

`g(4)=-12+5`

Add:

`g(4)=-7`

Now, substitute:

`f(g(4))=f(-7)`

Use the equation from f(x):

`f(x)=2x+7\\f(-7)=2(-7)+7`

Multiply:

`f(-7)=-14+7`

Add:

`f(-7)=-7`

So:

`f(-7)=f(g(4))=-7`

And that's our answer :)