Question

Let f(x) = −4x + 7 and g(x) = 10x − 6. Find f(g(x)).

Answer 1

try it, i will check

Answer 2

You must have some knowledge of this topic, so at least attempt the problem. Satellite and I may help you in anyway possible to ensure you understand the concept.

Answer 3

f(x) = -4x + 7
g(x) = 10x - 6

To get f(g(x)), simply replace the x in f(x) with g(x):

f(g(x)) = -4g(x) + 7

= -4(10x-6) + 7

= -40x + 24 + 7

Answer 4

do the last part and that's yo answer :3

Answer 5

Boldjon, please give them a chance to attempt the question, but thank you for your help.

Answer 6

okay, i was thinking -4(10-6)+7

Answer 7

hm... yeah that was close,
but the answer es
= -40x + 31
HARIBAAAA ur welcome
gtg :3

Answer 8

so then you distribute, and get
-40x+31

Answer 9

yeah but you need an \(x\) next to the \(10\)

Answer 10

yes ur right :3

Answer 11

ooh ok

Answer 12

not \[ -4(10-6)+7\] but rather \[ -4(10x-6)+7\]

Answer 13

lright! so what happens when they give you an extra number;
for example:
Let f(x) = x − 2 and g(x) = x^2 − 7x − 9. Find f(g(−1)).

Answer 14

it is actually easier, no algebra, just arithmetic

Answer 15

when you get it would you just plug in the x to get a number?

Answer 16

first compute \(g(-1)\) what do you get?

Answer 17

ummm, 1+7-9? is that what you meant??

Answer 18

yes, for a grand total of?

Answer 19

-1? oh what lol

Answer 20

it equals the same?

Answer 21

yes -1

Answer 22

now compute \(f(-1)\)

Answer 23

-3?

Answer 24

yup

Answer 25

so \[f(g(-1))=f(-1)=-3\] that is your answer

Answer 26

o wow! ill try one now

Answer 27

k good

Answer 28

Let f(x) = x + 8 and g(x) = x2 − 6x − 7. Find f(g(2)).

g(x)= 1
f(x)=10

so, f(g(2))=g(1)=10?

Answer 29

i think your \(g(2)\) is wrong, but you have the right idea

Answer 30

oh, oops!

Answer 31

i have one more question and that is it for functions!

Answer 32

did you get the final answer to this one?

Answer 33

10

Answer 34

Let f(x) = 5x + 12. Find f−1(x).
we did one of these right?

Answer 35

yes but we did it with numbers
now it is with variables
change x and y, solve \[x=5y+12\]for \(y\) in two steps

Answer 36

By f-1(x) you mean the inverse I assume. To do that just swap the values of your function with y<->x.

y=5x+12

becomes

x=5y+12

and now solve for y.

Answer 37

if you had something like 1/5x - 12/5, that would be the closest

Answer 38

ok so -12 + x=5y?

Answer 39

yes that is step one

Answer 40

both of you explaining is so difficult lol

Answer 41

ok! so would i divide by 5?

Answer 42

eys

Answer 43

yes

Answer 44

by divide, just write it

Answer 45

so \[\frac{ x-12 }{ 5 }\]

Answer 46

bingo

Answer 47

wooo thank you! I got a 90

Answer 48

yay (i guess)

Answer 49

100 would have been better

Answer 50

yeah inknow! i got the 2nd to last one wrong

Answer 51

that my g(2) was messed up for something?

Answer 52

prolly

Answer 53

but i got the curriculum, so thank you for taking your time and explaining to it me