Where is the idea that a majority of the houses of Congress must agree to pass a law come from? Is it from part of the Constitution?

Question

A majority in both houses must agree to pass a law for it to become a law, where is this stated?

Answer 1

More specifically, Article I, Section 7:

 

"Every Bill which shall have passed the House of Representatives and the Senate, shall, before it become a Law, be presented to the President of the United States; If he approve he shall sign it, .."

Answer 2

U.S. Constitution

 

http://www.usconstitution.net/consttop_law.html