Match the functions (f) with there inverse (f^-1).
f(x)= 3x + 1
f(x)=\frac{7 \cdot x-4}{8}
f(x)=3x + 3
f(x)= \frac{1}{3} x + 4
f(x) = \frac{x+6}{2}

Answer Choices
3x-12
2x-6
no inverse listed
(x-3)/3
(8x+4)/7
(x-1)/3

Question

Match the functions (f) with there inverse (f^-1).
f(x)= 3x + 1
f(x)=\frac{7 \cdot x-4}{8} 
f(x)=3x + 3
f(x)= \frac{1}{3} x + 4
f(x) = \frac{x+6}{2} 

Answer Choices
3x-12
2x-6
no inverse listed
(x-3)/3
(8x+4)/7
(x-1)/3

anonymous · Answer

for each of these substitute x in for y so like the first one instead of y=3x+1 do x=3y+1 and resolve for y.

anonymous · Answer

and what would you get?

anonymous · Answer

I'm not sure...I don't understand how to do it

anonymous · Answer

yeah

anonymous · Answer

ok. good luck with the rest! if you have troubles just ask again.

anonymous · Answer

and i made one error in the previous post so i will post again:

$$f(x)=3x+1$$

$$y=3x+1$$

$$x=3y+1$$

$$x-1=3y$$

$$\frac{ x-1 }{ 3 }=y$$

$$f^{-1}(x)=\frac{ x-1 }{ 3 }$$

anonymous · Answer

yes it would be :)

anonymous · Answer

ahh.. ok I've got it know thank you

anonymous · Answer

your welcome!

anonymous · Answer

I've did the others but I can't find the answer to the second or last one

anonymous · Answer

$$f(x)=\frac{7 \cdot x-4}{8} $$

is the second one so first switch the x and y

$$x=\frac{7 \cdot y-4}{8} $$

and multiply by 8 to get

$$8x=7y-4$$

Add 4

$$8x+4=7y$$

and divide by 7 to get

$$f^-1(x)=\frac{ 8x+4 }{ 7 }$$

anonymous · Answer

Now for the last one

$$f(x) = \frac{x+6}{2} $$

$$x=\frac{ y+6 }{ 2 }$$

$$2x=y+6$$

$$2x-6=y$$

$$f^-1(x)=2x-6$$

Hope this helps!

anonymous · Answer

thank you it does!