solution Approach:
the premise can be written as
A^[A->(BᐻC)]^[B->~A] => C
so to say its not valid prove That the left hand side can be Assigned a True value and Right hand side as False then the Premises are not valid.
So C=False
A=True
So B can be True or False in both the cases the right hand side can't be True So the premise is Valid