newhere

3 eq, 5 variables

correct sorry

write u(x,y)

x=-st/2+s, y=t+s, u=t+s/2

non linear

equations

if we have 3 equation with 3 variables can we write it as a function of two variable?

What should be my next step

I got $c_1=x-y$ and $u=1-c_2e^{-x}$

@geocalc33 I have this PDE

Someone can give me hand in PDE? if needed a paid online session?