Question

3x=5(mod 7); find x?

Answer 1

@ganeshie8 mod^

Answer 2

3x = 5 (mod 7)

this is defined as: 3x = 7k + 5, for any integer k

x = (7k+5)/3; let k= 0,1,2,3,4,...

5/3
12/3 = 4 mod 7
19/3
26/3
33/3 = 11 = 4 mod 7
....

seems to be a pattern

Answer 3

another way to see it

3x = 5 (mod 7)

3x-5 = 5-5 (mod 7)

3x-5 = 0 (mod 7)

means that 3x-5 is a multiple of 7
----------------------------

3x+2 = 5+2 (mod 7)

works just as well i spose