Answer with Step-by-step explanation:
Let F be a field .Suppose
and
![a\\eq 0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/op9pktx5vzj0bh9with7rnqsqcox42t3nj.png)
We have to prove that a has unique multiplicative inverse.
Suppose a has two inverses b and c
Then,
where 1 =Multiplicative identity
![ac=ab](https://img.qammunity.org/2020/formulas/mathematics/college/dyav6cbqqpnd3z99ywm1frl57nxgr1f5wu.png)
(cancel a on both sides)
Hence, a has unique multiplicative inverse.