Can anyone please help me solve this?
Use the change of variables x =
(1/3)(ξ − η) and y = (1/3)(ξ + 2η) to simplify the partial diﬀerential equation.
The simpiﬁed equation will have only one term on the left and one term on the right.
2uξξ + uξη − uηη = u

Question

Can anyone please help me solve this? 
Use the change of variables x =
(1/3)(ξ − η) and y = (1/3)(ξ + 2η) to simplify the partial diﬀerential equation.
The simpiﬁed equation will have only one term on the left and one term on the right.
2uξξ + uξη − uηη = u

anonymous · Answer

attachment

anonymous · Answer

I don't seem to know what to do as I am not given any function of u.

anonymous · Answer

$$2u _{ξξ} + u _{ξη} − u _{ηη} = u$$

anonymous · Answer

It's so hard :'(