Implicit Differentiation Question

[biochem850]

Homework Statement

2x^{3}-3x^{2}y+2xy^{2}-y^{3}=2

Homework Equations

The Attempt at a Solution

6x^{2}-(6xy+3x^{2}y')+(2y^{2}+4xyy')-3y^{2}y'=0

y'=\frac{-6x^{2}+6xy-2y^{2}}{-3x^{2}y+4xy-3y^{2}}


My text's solution is the same answer but with every every term having the opposite sign.

I don't see my error and I'm trying to determine why my answer is incorrect.

 

[scurty]

Your answer is correct! Remember you can multiply by \frac{-1}{-1} and the result is the same (multiplying by 1).

 

[biochem850]

Your answer is correct! Remember you can multiply by \frac{-1}{-1} and the result is the same (multiplying by 1).

How did I not catch that?

Thanks!