Is it possible to add sql query in Laravel?

I wanted to subtract values from 2 different columns in a table and the result would be shown in another column, is this possible? (so it's like an operation done in every row) If so, I do not have any idea how, please help me I am new to this T-T

If this is possible in phpmyadmin, I wanna know how.

Thank you in advance

via Chebli Mohamed