Jamboree Question of the Day - Day 94, Feb 15th 2011

a and b are the positive integers, and a is a prime number, if x ^2 - bx + a =0  has a positive integer solution, asks what is the value of (b-a)?

Answer (Posted on 17th): 1

A* 1 = a

A+ 1 = b

B–a=1