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Re: Solving a set of simultaneous equations using modulo arithmetic
Posted:
Dec 5, 1996 12:53 PM


ysr@grove.ufl.edu wrote:
: Hi, : Could any of you please suggest a method for solving linear : equations involving modulo arithmetic. We are not able to solve these : using conventional methods because they involve division.
Probably needs more information...
If you mean you require solutions to equations such as:
ax + by = c
then this is (rewritten in modulo terms) :
ax == c (mod y), where "==" stands for a congruence
Thus, to find x, simply multiply by te inverse of a:
a^{1}.a.x == a^{1}c (mod y)
x == a^{1}c (mod y)
No division is involved as a^{1} can be calculated, provide (a,y)=1, and then simply multiplied. But this is so simple that I'm sure that you're probably asking something else.
Thomas.



