Menu Close

Solve-2x-6-mod-8-




Question Number 137 by novrya last updated on 25/Jan/15
Solve 2x ≡ 6 (mod 8)
$${Solve}\:\mathrm{2}{x}\:\equiv\:\mathrm{6}\:\left({mod}\:\mathrm{8}\right) \\ $$
Answered by mreddy last updated on 10/Dec/14
gcd(2,8)=2, 2 divides 6   So there are 2 distinct solutions  Solutions for x are given by equation  2x+8y=6   The equation 2x+8y=6 has valid solutions for  x=3, x=7  So the solutions for 2x≡6(mod 8) are  3 (mod 8) and 7 (mod 8)
$$\mathrm{gcd}\left(\mathrm{2},\mathrm{8}\right)=\mathrm{2},\:\mathrm{2}\:\mathrm{divides}\:\mathrm{6}\: \\ $$$$\mathrm{So}\:\mathrm{there}\:\mathrm{are}\:\mathrm{2}\:\mathrm{distinct}\:\mathrm{solutions} \\ $$$$\mathrm{Solutions}\:\mathrm{for}\:{x}\:\mathrm{are}\:\mathrm{given}\:\mathrm{by}\:\mathrm{equation} \\ $$$$\mathrm{2}{x}+\mathrm{8}{y}=\mathrm{6}\: \\ $$$$\mathrm{The}\:\mathrm{equation}\:\mathrm{2}{x}+\mathrm{8}{y}=\mathrm{6}\:\mathrm{has}\:\mathrm{valid}\:\mathrm{solutions}\:\mathrm{for} \\ $$$${x}=\mathrm{3},\:{x}=\mathrm{7} \\ $$$$\mathrm{S}{o}\:\mathrm{the}\:\mathrm{solutions}\:\mathrm{for}\:\mathrm{2}{x}\equiv\mathrm{6}\left({mod}\:\mathrm{8}\right)\:\mathrm{are} \\ $$$$\mathrm{3}\:\left(\mathrm{mod}\:\mathrm{8}\right)\:\mathrm{and}\:\mathrm{7}\:\left(\mathrm{mod}\:\mathrm{8}\right) \\ $$