How do I differentiate y' when it appears in an equation?

[chrisdk]

Homework Statement

Differentiate:

$$y'''+ty''+y'+y'=0$$

Homework Equations

The Attempt at a Solution

I tried to use this definition:

$$(y')'=y''$$

I'd be thankful, if somebody could show me the rules of differentiating y'.

 

[Dick]

You've got it. (y')'=y'', (y'')'=y'''. Etc. Don't forget to use the product rule on ty''.