Question

Solve the congruence 3x=2(mod4)

Answer 1

Explanation:

jello :

3x=2(mod4)

multiply by ; 5

5×3x=5×2(mod4)

15x=10(mod4)

but : 15= -1 (mod4) and 10= 2 (mod4)

-x=2 (mod4)

now multiply by ; -1 you have : x= -2 (mod4)

-2=2(mod4)

conclusion : x=2 (mod4) means : x=4k+2 k in Z