Question

According to smith, when private individuals are left free to seek their own interests in free markets, they will inevitably be led to further the public welfare by an "invisible hand"

Answer 1

This is, in fact, true. Smith believed that private individuals who were left free to seek out their own interests in a free market would eventually be led to further the public welfare by an invisible hand, this was his defense of free markets on the grounds of utilitarianism.