a. If B is a natural number and a = B + 1, then the greatest common factor of a and B is______ The least common multiple is______ .

a. If B is a natural number and a = B + 1, then the greatest common factor of a and B is______ The least common multiple is______ .

A = B + 1 (A and B are natural numbers), so a and B are coprime numbers, then the greatest common factor of a and B is 1, and the least common multiple is ab; so the answer is: 1, ab