
linear congruence: complete soln: 4x(is equivalent to) 5(mod 21) @Mathematics
8 years ago
when I did the EEA I got 4(-5) + 21(1) = 1
8 years ago
but then you have to mult by 5
8 years ago
then x=xnot+bn/d
8 years ago
when I multiplied by 5 I got 4(-25) + 21(5) = 5
8 years ago
o ya then xnot is -25
8 years ago
x=-25+21n
8 years ago
your way of writing things is different then how I did it
8 years ago
you have to find all solutions
8 years ago
yeah I got x is congruent to 17 (mod 21)
8 years ago
k so where do i go from here
8 years ago
from the EEA you just convert it back into congruent form I think
8 years ago
so x is congruent to -25 is congruent to what
8 years ago
so 4(-25) congruent to 5 (mod 21) so x congruent to -25 (mod 21/1) is the complete solution and that is equivalent to x congruent to 17 (mod21/1
8 years ago
since (-25) is some solution for x
8 years ago
then you just put it into the Linear Congruence Theorem, V1
8 years ago
to get the complete solution
8 years ago
o crap ok now i see it
8 years ago
I don't know this stuff super well either lol
8 years ago
did you show eea?
8 years ago
yeah I put it in there
8 years ago
but theres no room
8 years ago
the EEA for those were really short so I just wrote it in there tiny
8 years ago
have you done any other problems on the assignment? I'm stuck on 5c lol
8 years ago
only up to 3
8 years ago
ok well I guess I might try asking on here again then
8 years ago
metoo
8 years ago
4x(is equivalent to) 5(mod 21) 21 | 4x-5 21|4*(-4)-5 Hence -4 is a solution. ??? I am not sure.
8 years ago
i dunno
8 years ago




