Partial differential equation problem

[sam topper.]

Homework Statement

using the method of separation of variables, solve ∂u/∂x=4∂u/∂y, where $u=3e^-y - e^-5y$ when x=0.

Homework Equations

The Attempt at a Solution

let u(x,y)=X(x)Y(y)
=XY.

 

[tiny-tim]

hi sam!

let u(x,y)=X(x)Y(y)
=XY.

good

what next? ​