Question

Given the following functions f(x) and g(x), solve (f + g)(5) and select the correct answer below: (1 point)

f(x) = 8x − 13

g(x) = x − 9

a 23
b 27
c 31
d 40

Answer 1

Are you good with these or no?

Answer 2

@fabgirl1994

Answer 3

I'm not sure how to do them. My lesson will not load.

Answer 4

Okay! It's been a little while since I have done these but I can help you. Just disregard any errors that I may possibly have. xD

Answer 5

When we have \[f(x)= x ; g(x)=x\] and we want to combine them ; \[f(g(x))\]

Answer 6

or in this case we are adding them together so we have
f(x) = 8x − 13

g(x) = x − 9

Answer 7

Right

Answer 8

Okay, you are following along. :)
This is rather simple since are just adding the two functions together.

Answer 9

Yes

Answer 10

f(x) = 8x − 13
g(x) = x − 9
(f+g)= (8x-13 + x - 9 )

Answer 11

Sorry for taking so long, OS isn't letting me copy the equations to make this go by faster

Answer 12

Can you add together like terms for me?

Answer 13

You're fine. I'm following along.

Answer 14

Would it be: 8x-3?

Answer 15

I got that because 8x and and x combined. Then I did 13-9=3

Answer 16

(f+g)= (8x-13 + x - 9 )
Let me see :)
(8x-13+ 1x - 9
(9x - 22)
is what I get.

Answer 17

@mathmale am I doing everything correctly?

Answer 18

@Maddy1251 : Your f(g(x)) does not describe the operation required in this problem.
Please explain what the goal of the problem is, if it's not f(g(x)).

Answer 19

OKay, i get that. I wasn't sure if I added the 1x on or not to the 8. And I seen a + and a - after the 13 so wasn't sure if I added or subtracted 13 and 9.

Answer 20

@mathmale I understood after typing f(g(x)) was unrelated to this. This is adding two functions together.

Answer 21

So how do I get an answer from 9x-22?

Answer 22

Yes, that's right; it's addition.

Answer 23

@fabgirl1994 you have x = 5. You substitute.

Answer 24

@mathmale yes you do. It my all my fault mentioning that. I was thinking one concept when the concept didn't need applied.

Answer 25

Right. Add functions f and g. THEN, let x=5.

Answer 26

well... (f+g)(x) where ; x=5

Answer 27

So x = 5, but thats not an answer choice, what now?

Answer 28

Yes, that is what I had her do. 9x - 22.

Answer 29

I have the answer choices 23, 27, 31 and 40.

Answer 30

(f+g)(5) = 9x-22 = ____ ; when x=5

Answer 31

9(5)-22.

Answer 32

Thanks! I have a few more, Ill post the question.

Answer 33

Yes, I agree with that. You have successfully combined the 2 functions f and g.
Fabgirl1994: Let's concentrate on understanding, not just on the answer.

(f+g)(x)=9x-22.

what happens if you now substitute x=5 into the right side of this equation?

Answer 34

I got 23 :)

Answer 35

There ya go fabgirl.

Answer 36

Thanks for catching my fault before @mathmale

Answer 37

Mind posting further questions as fresh, new posts? The current one has been around for a while. ;)