great!

further calcul tell us:

1) 3a(5-b) = b, a = 2/(6-3p), b = 3+p ==> p = -1, a=2/9, b=2

2) 3a(5-b) = 2, a = 2/(6-3p), b = 3+p ==> p = -1, a=2/9, b=2

both pathes lead to your original wrong answer f(0)=8/9

this proof that you are "computer" major, just a little short in analysis and reasoning.

 

Mes respects monsieur!