Example of a regular element in noncommutative rings

229 Views Asked by At

Whats an example of ring $A$ which is not commutative and contains an element $x\in Z(A)$ such that the left multiplication by $x$ is an injection and $x$ is not a unit?

1

There are 1 best solutions below

4
On BEST ANSWER

Let $A=M_2(\Bbb Z)$ be $2\times 2$ matrices over $\Bbb Z$ and let $x=2I$ be twice the identity.