Question

Given the function f(x) = 4(x+3) − 5, solve for the inverse function when x = 3.

−21

−16

−10

−1

Answer 1

do you know how to find inverse function ?

Answer 2

hartnn that is y i asked the question cause i forgot how to find the inverse

Answer 3

ok,
let y = 4(x+3) − 5
isolate 'x' from this equation.
start by adding 5 on both sides.

Answer 4

ok so it would be 5+y=4(x+3)

Answer 5

yes, now divide by 4 on both sides...

Answer 6

ok so it would be \[\frac{ 5+y }{ 4 }=\frac{ x+3 }{ 4 }\]

Answer 7

on tight side, 4(x+3)/4 is just x+3
got this ? the 4 gets cancelled

Answer 8

oh ok

Answer 9

so,
(5+y)/4 = x+3
just subtract 3 from both sides and you would have isolated 'x' ! :)

Answer 10

0k so when i subtract 3 do i subtract it from 5 or put it outside the perenthisis

Answer 11

outside paranthesis, as there is a fraction, keep the -3 alone on left side

Answer 12

ok so -3(5+y)/4=x

Answer 13

did you multiply ?
its actually (5+y)/4 -3 = x
ok ?
so your inverse function is just
(5+y)/4 -3

Answer 14

i mean (5+x)/4-3

Answer 15

now how do i get it to one of my answer options

Answer 16

we wanted inverse function when x=3
so just plug in x = 3 there!

Answer 17

ok so it would be 8/4=2-3=-1

Answer 18

correct! good work :)

Answer 19

another method to do the same thing is to put f(x) = 3
4(x+3) − 5 = 3
will also give you x = -1 :)

Answer 20

ok thanks man

Answer 21

welcome ^_^