No, believing/ trusting in Christ is
contrasted with works for justification, not equated with it:
"4Now to the one who works, wages are not credited as a gift but as an obligation. 5However, to the one who does not work but trusts God who justifies the ungodly, their faith is credited as righteousness." - Romans 4:4-5
No, Paul said faith and law are diametrically opposed:
"12The law is not based on faith; on the contrary" - Galatians 3:12
And even if faith was a law, for surely Paul speaks of a 'law of faith' (Romans 3:27), he does not include it in the works that cannot justify but instead says it
excludes any boast of self-righteous:
"27Where then is boasting? It is excluded. By what kind of law? Of works? No, but by a law of faith." - Romans 3:27
A 'law of faith' actually
nullifies the law of works and removes any boast of works in justification that might somehow make having faith a self-righteous work of law.
I am saved because I believe:
30 “Sirs, what must I do to be saved?”
31They said, “Believe in the Lord Jesus, and you will be saved, you and your household.” - Acts 16:30-31