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SNOOTCHIEBOOCHEE
Oct12-08, 07:08 PM
1. The problem statement, all variables and given/known data

let a,b \inG show that ax=b has a unique solution in G

3. The attempt at a solution

i know what needs to be done, i just dont know how to do it.

Want to prove:

1. There is a solution
2. solution is unique

to prove uniquness of a soltuion just suppose you have a different solution x' and show that x'=x


to show that there is a solution (im not sure this part is right, cause it seems too simple) simply multiply (left) by a^{-1}

that is a^{-1}*ax=a^{-1}b

we can do this because a is in the group, which implies a^{-1} is in the group

THis is where i am stuck... i really dont know how to proceed. Have i even done the first part right?

any help appreciated

morphism
Oct12-08, 07:58 PM
So you showed that there is a solution, namely x=a^{-1}b. To show that x is unique, use the fact that in a group, inverses are unique.