d_1+d_2+...+d_6= 36 iff (d_1-6) (d_2-6) ... (s_6 -6) = -36, digits \ne 6
Source: 2007 Moldova JBMO TST p1
February 20, 2021
number theoryDigitsSumProductsum of digits
Problem Statement
The numbers are distinct digits of the decimal number system other than .
Prove that if and only if .