The hunt for X.
Isolating the variable to find its value.
Ancient Egyptians solved these using the 'Method of False Position'.
Undo operations in reverse PEMDAS order (SADMEP).
In Plain English: The goal is to get X alone. It's like unwrapping a gift. If X is multiplied by 2 and then has 5 added to it, you must subtract 5 and then divide by 2.
In The Real World: Budgeting. 'I have $100. Tickets are $20. How many can I buy?' 20x = 100.
Forgetting to do the operation to BOTH sides of the equals sign. Balance the scale!