The quadratic equation x^2-3x+2=0 has the "correct" number of solutions modulo 5 and 7. However, modulo 6 the equation has four solutions; namely, 1, 2, 4, and 5. For what positive integers n does the equation x^2-3x+2=0 have exactly two incongruent solutions modulo n?

(In reply to re(2): Proof by Richard)

Thanks, Richard.  And thanks for not divulging your solution before others had a chance to show their solutions.

Will you "never tell" how you would solve the problem if the equation was x^2-4x+3=0?

Posted by McWorter on 2005-09-03 23:38:59