Question

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

-40x + 24

-40x + 31

-40x + 64

-40x + 70

Answer 1

@nikato

Answer 2

Hey, so for these kinds of question you're basically substituting g(x) into f(x) where ever the x is.

So,

\[f(g(x)) \implies -4(10x-6)+7\]

now evaluate

Answer 3

\(\normalsize\color{blue}{ f(x) = -4x + 7\LARGE\color{white}{ \rm │ }}\)
\(\normalsize\color{blue}{ g(x) = 10x - 6\LARGE\color{white}{ \rm │ }}\)


\(\normalsize\color{blue}{ f(g(x)) = -4(10x - 6) + 7\LARGE\color{white}{ \rm │ }}\)
\(\normalsize\color{blue}{ f(g(x)) = -40x +24 + 7\LARGE\color{white}{ \rm │ }}\)
\(\normalsize\color{blue}{ f(g(x)) = -40x +31\LARGE\color{white}{ \rm │ }}\)

Answer 4

Thanks @SolomonZelman Can I have One more question

Answer 5

I have one more I mean

Answer 6

sure

Answer 7

shore

Answer 8

Let f(x) = 2x - 6. Solve f^-1(x) when x = 2.

-5

4

-2

7

Answer 9

Let me let me!

Answer 10

go ahead

Answer 11

Ok when the notation f^-1(x) implies you're looking for the inverse, so first lets find the inverse...

Replace f(x) with y
Switch x's and y's, so put x where y is and x where y is.
Solve for y
Replace y with f^-1(x)

Once you have the inverse, sub 2 for x and evaluate :)!

Answer 12

I don't get it

Answer 13

\[f(x) = 2x-6\]

we have to find the inverse, so following the steps I gave you,

\[y=2x-6\]

now switch the x's and y's around,

\[x=2y-6\]

now solve for y,

\[y=\frac{ x+6 }{ 2 }\]

\[\implies f ^{-1}(x) = \frac{ x+6 }{ 2 }\]

now substitute 2 for x and solve.

Answer 14

Okay so
8/2 =4

Answer 15

So B

Answer 16

One more please

Answer 17

Yeah.

Answer 18

Let f(x) = 24/3x -2 Find f(-2).

-6

-3

3

6

Answer 19

What do you think?

Answer 20

If f(x) implies 24/3x-2
f(-2) implies ...?

Answer 21

I believe it is 24/12

Answer 22

Is it \[f(x) = \frac{ 24 }{ 3x-2 }~~~or~~~f(x) = \frac{ 24 }{ 3x }-2\]

Answer 23

Either way just plug in -2 for wherever the x is.

Answer 24

I am sorry I meant the 1st

Answer 25

K well just plug in -2 for x

Answer 26

3 x -2 = -6 - 2 = 8

Answer 27

Ah so the answer is 3

Answer 28

-3