First there is a good tutorial for "LaTex" formatting that is used on this board. Just start with "[ tex ]" and end with "[/ tex ]" (without the spaces):Introducing LaTeX Math Typesetting

Please show what youhavedone. What did you get when you differentiated and put y, y', and y'' into the equation?

(You don't really need the "+r" in the exponent because this not really a Frobenious equation- the leading coefficient is never 0 so it is sufficient to look for a solution of the form )