In the plane rectangular coordinate system, it is necessary for the line y = 2x to move 3 units to the left

In the plane rectangular coordinate system, it is necessary for the line y = 2x to move 3 units to the left

There's no need to remember that. There's a rule
"Left plus right minus" fits most of the similar rules
Move 3 units to the left, then you only need (x + 3) abscissa + 3 to be OK. It may be more convenient to remember the form directly like this