Question

Can someone teach me how to do this sort of problem? Let f(x)=-5x-4 and g(x)=6x-7. Find f(x)+g(x)

Answer 1

stick a plus sign between them

Answer 2

after that, combine like terms

Answer 3

So f(x)=-5x-4+g(x)=6x-7?

Answer 4

\[-5x-4+6x-7\]

Answer 5

OH
ok, so -5x-4+6x-7
Then X-11

Answer 6

\[\overbrace{-5x-4}^{f(x)}+\overbrace{6x-4}^{g(x)}\]

Answer 7

And that's my answer?

Answer 8

typo there, i meant
\[\overbrace{-5x-4}^{f(x)}+\overbrace{6x-7}^{g(x)}\]

Answer 9

So it's x-11?

Answer 10

but yes, you are correct \(f(x)+g(x)=x-11\)

Answer 11

Ok. There's also one more type of question, can I get help on it?

Answer 12

sure

Answer 13

f(x)=x^2-16 and g(x)=4+4. find f/g and its domain. This one has me thoroughly confused.

Answer 14

put a fraction bar between them

Answer 15

i assume there is a typo in your question

Answer 16

So (x^2-16)/(x+4)?

Answer 17

yes, that is the first step
then some algebra

Answer 18

before the algebra, make sure to find the domain
since you cannot divide by zero, set \(x+4=0\) get \(x=-4\) and then say "all real numbers except \(-4\)"

Answer 19

x^2-16/(x+4=0)
x=-4
-4^2-16/0
16-16/0
0/0?
I think I did that wrong.

Answer 20

yes, i think so
you confused finding the domain with evaluating at \(x=-4\)
you CANNOT

Answer 21

evaluate at \(x=-4\) which is why the domain is all real numbers EXCEPT for \(-4\)

Answer 22

OH

Ok, I think I get it

Answer 23

you still have some algebra to do

Answer 24

x-4, and the domain is all real numbers except x=-4?

Answer 25

yes

Answer 26

Okay.
Thanks for the help!

Answer 27

yw
who does math on christmas eve? isn't it a holiday or something?

Answer 28

It is, but I like to work ahead in class so if I get sick or something I don't have to worry as much.

Answer 29

good luck!