![SOLVED:Definition 0.1. An element a in a ring R is said to be invertible , or a unit, if there exists an element b € R such that a. b = 1. SOLVED:Definition 0.1. An element a in a ring R is said to be invertible , or a unit, if there exists an element b € R such that a. b = 1.](https://cdn.numerade.com/ask_images/bcc8fa970d0d475dad150b06199825ab.jpg)
SOLVED:Definition 0.1. An element a in a ring R is said to be invertible , or a unit, if there exists an element b € R such that a. b = 1.
![abstract algebra - Let $R$ be a ring. Define a circle composition ◦ in R by $a ◦ b =a+b-ab$, $a, b ∈ R$. - Mathematics Stack Exchange abstract algebra - Let $R$ be a ring. Define a circle composition ◦ in R by $a ◦ b =a+b-ab$, $a, b ∈ R$. - Mathematics Stack Exchange](https://i.stack.imgur.com/J4hBx.png)
abstract algebra - Let $R$ be a ring. Define a circle composition ◦ in R by $a ◦ b =a+b-ab$, $a, b ∈ R$. - Mathematics Stack Exchange
![SOLVED:For 2 2, let Gq be the group of invertible elements in the ring Z/qz Each Gy gives rise to function on 2 defined by e([n]) if gcd(n.4) = 1; x(n) if SOLVED:For 2 2, let Gq be the group of invertible elements in the ring Z/qz Each Gy gives rise to function on 2 defined by e([n]) if gcd(n.4) = 1; x(n) if](https://cdn.numerade.com/ask_images/0998904a0add4739a19a1f865b042a61.jpg)