Answer: Hi!
GEMDAS is the guideline that you would use to solve a algebraic expression. It tells you the order of which things you should solve or simplify first.
G. Groupings. (There is a similar expression called PEMDAS that is a bit easier to understand, where the P stands for parentheses, brackets, etc.)
E. Exponents.
MD. Multiplication and Division, right to left.
AS. Addition and Subtraction, right to left.
Hope this helps!