Thanks. Where does the other solution y = -2 come from?
No, because the k in the numerator and the k in the denominator are the same k. They would both have to change.If you change the K in the denominator to +K, then the answer is y = -2...
I agree with you up to here:
Replacing with yields
Multiplying the negative sign in yields
Now, finally, one more trick: replacing with will, I think, finish off the problem.