Standard form for equations will place all the terms with variables on one side of the equation, typically the left and in alphabetical order, and the constant term on the other side, typically the right. Its nice to keep all the equals you write above one another so that the "side" concept is easier to see as the work gets done.
So only a little algebra is needed to make the 4x term "go over to the left side":
2y = 4x + 5
-4x -4x
-4x + 2y = 5
You could have written it as 2y - 4x = 5, since it is equivalent however typically the variable terms are listed in alphabetical order. If it's not too clear why it turned from a subtraction expression into an addition expression, remember that you can rewrite any subtraction expression as a sum of terms that have a "switched sign" for the term after the subtraction symbol. Let me know if you need that explained better. Hope that helps!
