Differential equation substituition of new terms

[delsoo]

Homework Statement

for this question, i sub u=xy and try to eliminate y in my working.. but how should i proceed since the term ux cannot be separated

Homework Equations

The Attempt at a Solution

 

[ehild]

I do not understand what you did. Your u-s and y-s look the same. Eliminate y by replacing it with u/x. Note that xdy/dx+y=du/dx, and xy²=u²/x.

ehild