How to store user defined scoring formulas? First post, so apologize if I have not chosen the best spot for it:

If I had table of values, let's say corresponding to a question number and its corresponding answer, what is the correct way to plan a database to allow users to store formulas to calculate a score based on said answers? 

Example:

Let's say I have a table of answer given to a series of questions:

Question_and_answer_table

ID   Answer
 1       3
 2       5
 3       7
 4       9 

Then I have 3 different users, User1, User2, User 3.

If I want each user to be able to define how they want to weigh the answers to determine a final score


  ex: User1: A1*3-A2*2+A3*7*A4=SCORE 


what's the best way to handle storing a formula for each user? 

Thank you for your time and help!

Cheers
You can have a table of weights -- that is, an association of user with each question and how much that answer is weighted. Then you can give each user their own weight for each answer.

create table Weights(
    UserID     int not null references Users( ID ),
    AnswerID   int not null references Answers( ID ),
    Weight     int default 1, -- For Ux: Ax * Weight,
    constraint PK_Weights primary key( UserID, AnswerID )
);


I've shown the weight as an integer but you can change that if you want fractional values (A1 * 3.5 + A2 * -2.75 + A3 * 7 + A4 * 3.1415 = SCORE ).