Question

Let f(x) = 5x + 12. Find f–1(x)

12x + 5

1/5x+12

5/x-12

x-12/5

Answer 1

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 2

wut? this is confusing

Answer 3

Do you know how to solve the equation for y, that means to rearrange the equation I have given,

x=5y+12

to have y alone and all the numbers on x's side.

Answer 4

let me see,

Answer 5

one moment

Answer 6

y=5x+12?

Answer 7

isnt that what is up their ??

Answer 8

No man.. you need to do algebraic operations. To get 12 on the other side, you need to subtract 12 from both sides, so you will have,

x-12 =5y

Now what do you do with the 5 that is multiplying y. How do you move that from the right side to the left side?

Answer 9

oh man this is tuff, i remember learning this last year.

Answer 10

hold on

Answer 11

Dude, this is as easy as math gets.. It aint tuff.. trust me.

Answer 12

i give up, though, I was thinking this, 5y+x=12

Answer 13

What grade are you on?

Answer 14

junior, but I failed segment 2 of algebra in my sophomore year bc i slacked off

Answer 15

i guess you have the right to tell me im dumb

Answer 16

no dude you're not dumb, I just wanted to know how to explain the problem to you. Alright, check this out.

x-12=5y

You divide both sides by 5 because that number is multiplying y on the right side. So when you divide both sides you will cancel out the one that's multiplying y and.

Therefore your equation now becomes,

x/5 - 12/5 = y

That is the inverse of your initial function

Answer 17

oh, i get it

Answer 18

how would i solve for this question?

Answer 19

Are those the only possibilities that you have?

Answer 20

yep

Answer 21

None of them are correct.

Answer 22

which one would be the closest?

Answer 23

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

Answer 24

ill just guess. Thanks for your help though!

Answer 25

lol, sure you're welcome.