Question

Let f(x) = 7x - 13. Find f^-1(x).

Answer 1

13x-7
7/x+13
x+13/7
1/7x-13

Answer 2

well.. to get the inverse "relation", we simply first swap about the variables..... thus \(\bf f(x) ={\color{brown}{ y}}= 7{\color{blue}{ x}} - 13\qquad inverse\implies {\color{blue}{ x}}= 7{\color{brown}{ y}} - 13\) and solve that for "y"

Answer 3

shouldn't it be +13 ?

Answer 4

@jdoe0001 @SolomonZelman Isn't the answer y = 1/7x +13/7

Answer 5

@Frostbite

Answer 6

hmmm what did you get after solving for "y"?

Answer 7

y = 1/7x +13/7

Answer 8

Weird answer, huh?

Answer 9

I just thought that + would be the inverse action to -.

Answer 10

hmmm you may want to recheck your simplification

Answer 11

Alright one sec

Answer 12

I have come to another dead end as I got:
y=7x−13

Answer 13

x = 7y - 13

try "adding" 13 to both sides
then
divide both by 7

Answer 14

I see what you did, jdoe, I misinterpreted you.. of course you are right (as always)

Answer 15

So lets see:
x + 13 = 7y - 13 + 13
13x = 7y
---------
7 7
13x
--- = y
7

Answer 16

13x/7

Answer 17

hmm x+13 = 13x?