[SOLVED] Implicit Differentiation

[hard_assteel]

-4x^2+3xy+4y^3=-328

This is at the point (1,3)


[b]2. Relevant equations



3. The attempt at a solution

here is my work

-4x^2+3xy+4y^3=-328
-8x+3xy'+3y+12y^2y'=0
-8x+3y=-3xy'-12y^2y'
-8x+3y=[-3x-12y^2]y'
y'=(-8x+3y)/(-3x-12y^2)
plug in x=1,y=3 then solve and get
m=-12/67
can you find the error?
It would be very much appreciated
thank you.

[cristo]

Try plugging in your values for x and y again.

[hard_assteel]

hey thankx, i accidently posted this question twice.