Question

If f(x)=(3x+1)/5, then find:
A.) f(3) and f(-7) - I got f(3)=2 and f(-7)=-4 is this right?
B.the value of k if f(k)=8
C. Find a value of k such that f(k)=k

Answer 1

\[f(x) = (3x+1) \over 5\]

Answer 2

A is good
now B

Answer 3

let the RHS =8, solve for x

Answer 4

I'm confused about where k came into play

Answer 5

just letter, ignore it.

Answer 6

f(x) = (3x+1)/5
f(k)=(3k+1)/5
same!!

Answer 7

it is not important

Answer 8

Okay so it makes no difference then??

Answer 9

So b is f(8)=5?

Answer 10

No, I said , let the right hand side =8, solve for x

Answer 11

it meant (3x+1)/5=8

Answer 12

now, solve for x

Answer 13

So x=13??

Answer 14

Part C:

\[f(k)=\frac{ 3k+1 }{ 5}=k\]
\[k=\frac{ 1 }{ 2}\]
(answer)

Answer 15

Thank you guys!!