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

Answer:

-7

Step-by-step 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 :)