Solving for k and m in f(x) = kx+m

[Rectifier]

The problem

Find k and m.

$f(x) = kx+m$

$f(3x-2)=6x-5$

The attempt

$t = 3x - 2$

$f(t) = kt + m \\ f(3x -2) = 2(3x-2) - 1 \\ f(t) = 2t - 1 \\ f(t) = kt + m \\ k=2 \\ m=-1$

I am not sure if I am doing this right...

 

[mafagafo]

You can numerically test your work. Do it.

I am not sure if I am doing this right...

Checking your work numerically (when possible) is a good way to check your calculations even if you think you are doing it right.