differentiation of exponential

[towens81]

problem:
5 x^3 e^1 y + 5 y^4 e^3 x = 11
so i took the derivative of each term first using the multiplication rule to get:
15x^2 e^y + e^y 5x^4 dy/dx + 20y^3 e^3x dy/dx + 5y^4 3*e^3x = 0
I isolate dy/dx
15x^2 e^y + 5y^4 3*e^3x = - (e^y 5x^4) - (20y^3 e^3x) dy/dx
dy/dx= (15x^2 e^y + 5y^4 3*e^3x) / (- (e^y 5x^4) - (20y^3 e^3x))
the computer program im using says this is wrong and im stuck
any help is appreciated

 

[arthur ohlsten]

I shall rewrite the equation
(5e)x^3y + (5e^3)xy^4=11

derivative of x^3y with respect to x is [x^3 dy/dx + y 3x^2]
5e is a constant

derivative of xy^4 with respect to y is [x 4y^3 dy/dx + y^4]
5e^3 is a constant

Arthur