$\textbf{Normal subgroup}$
A subgroup $N$ of a group $G$ is a normal subgroup of $G$ if for all elements $g$ of $G$ the corresponding left and right cosets are equal, that is $$gN=Ng\quad\text{for all}\quad g\in G.$$
$\textbf{Normal subgroup}$
A subgroup $N$ of a group $G$ is a normal subgroup of $G$ if for all elements $g$ of $G$ the corresponding left and right cosets are equal, that is $$gN=Ng\quad\text{for all}\quad g\in G.$$
copied
๐๐จ๐ซ๐ฆ๐๐ฅย ๐ฌ๐ฎ๐๐ ๐ซ๐จ๐ฎ๐ฉ
A subgroup ๐ of a group ๐บ is a normal subgroup of ๐บ if for all elements ๐ of ๐บ the corresponding left and right cosets are equal, that is
๐๐=๐๐ forย all ๐โ๐บ.