How do I store an algebra problem with the answer to retrieve later?

Answer 1

You can store a formula inside a special string variable.

Do as follow :
"2+3"->str1

str1 is inside "Vars" menu than choose  "String".

 

Then you can execute the formula with "expr("

expr(str1

Answer :

5

You can also do :

expr(str1 -> A

So you have formula and answer :)