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!