Question

If f(x)=3x and g(x)= x + 4

f[g(1)]

Please help I don’t know how to do the formula. Please just teach me the steps.

Answer 1

f[g(1)]= 15

Explanation:

f(x)=3x

g(x)=x+4

so you are asked to find fof(g(1))

you first find g(1)= 1+4=5

now you substitute it into f(g(1))

so you now have f(5)

f(5)= 3×5=15

Answer 2

`f(g(1))=15`

Explanation:

`f(x)=3x\\g(x)=x+4\\f(g(1))`

First, you need to evaluate
`g(1)`:

`g(1)=(1)+4\\g(1)=5`

Now, you plug this into
`f(x)` and evaluate
`f(5)`:

`f(5)=3(5)\\f(5)=15`

Now you know
`f(g(1))=15`.