Question

New Question! @satellite73 screenshot below

Answer 1

the amount of numbers in this one is confusing me big time.

Answer 2

aint to numbers in this one, this is straight up algebra

Answer 3

do i do this like all the other ones?

Answer 4

i dont see any cords to do it off of though to fill in for X

Answer 5

\[f(x)=7x+3\\
g(x)=2x-5\\
(f+g)(x)=7x+3+2x-5\] combine like terms as the math teachers say

Answer 6

oh ok so.

9x-2

Answer 7

(f+g)(x)=7x+3+2x-5

Answer 8

which means (f+g)(x)=9x-2

Answer 9

yes i agree

Answer 10

(f-g)(x)=

so lemme try this one

Answer 11

7x+3-2x-5?

Answer 12

ok don't forget to use parentheses when you subtract

Answer 13

see?
you forgot already

Answer 14

or would it be
(7x+3)-(2x-5)

Answer 15

second one

Answer 16

i caught myself soon as i posted it! :P

Answer 17

so that means it would be... oh gosh hold on math blanking right now

Answer 18

would i factor through or am i overthinking?

Answer 19

5x-2?

Answer 20

no not 5x-2... im thinking factoring? or sign distribution?

Answer 21

\[(7x+3)-(2x-5)\] is right, \(5x-2\) is not

Answer 22

so it would be.

7x+3-2x+5

Answer 23

yes

Answer 24

so 5x+8

Answer 25

yes

Answer 26

(fg)(x) this one is multiplication. so factoring?

Answer 27

(7x+3)(2x-5)

Answer 28

yes

Answer 29

they might want you to multiply it out, not sure

Answer 30

so 14x^2-35x+6x-15

Answer 31

so therefore 14x^2-29x-15

Answer 32

yes

Answer 33

ill try the last one now! i think its finally clicking for this type!

Answer 34

good
there is nothing much to do for the last one

Answer 35

(f/g)(x)=(7x+3)/(2x-5)

Answer 36

yes

Answer 37

and i will have to simplify that somehow?

Answer 38

no

Answer 39

because it cant be?

Answer 40

because you can't

Answer 41

ok! now how do i find the domains?

Answer 42

the domain of any polynomial is all real numbers, so all real numbers for the first three

Answer 43

for the last one, the fraction, you cannot divide by zero, set \[2x-5=0\] and solve for \(x\)
then say "all real numbers except" whatever you get for the answer

Answer 44

so lets go with (f+g)

(f+g)(x)=9x-2

Answer 45

so the domain for 9x-2 is...

Answer 46

domain is all y's?

Answer 47

all real numbers for first three

Answer 48

oh it wants interval notation!

Answer 49

(-infinity,-2]

Answer 50

?

Answer 51

\[(-\infty, \infty)\] for the first three

Answer 52

oh... why infinity for both?

Answer 53

does the y intercept mean nothing in these type of questions for domains?

Answer 54

yes, it means nothing

Answer 55

or are these always going to be inf,inf when its like those?

Answer 56

for the polynomials (the ones not fractions) yes

Answer 57

and then for the frac its

2x-5=0

so 2x=5

Answer 58

so x=5/2

Answer 59

thats not right... what did i do wrong

Answer 60

right
putting that answer in interval notation is annoying but we can do it

Answer 61

it is all numbers except that one , so \[(-\infty, \frac{5}{2})\cup (\frac{5}{2},\infty)\] is what you have to write

Answer 62

woah... can you explain what the U means and the Upside down U means in relation to these? i never understand those...

Answer 63

means "union" one or the other or both
basically it is a long winded way of saying everything but \(\frac{5}{2}\)

Answer 64

oh i see! ok! so ill skip all that are like we did and i found one we havent touched on. ok if i make a new question?