if $R$ is a commutative ring with unity and $A$ is a proper ideal of $R$ ,then $R/A$ is a commutative ring with unity

Question

How should I prove that :
if $R$ is a commutative ring with unity and $A$ is a proper ideal of $R$ ,then show that $R/A$ is a commutative ring with unity?
commutative part will hold because if $R$ is commutative then $R/A$ has to be commutative

How to show that $R/A$ will have unity?

Answer 1

If $1\in R$ then $$ (1+A)(r+ A)=(r+A)(1+A)=r+ A$$

Hence $1+A$ is unity