How do I solve this one?
(2x - y + 4)dy + (x - 2y + 5)dx = 0
Find the point of intersection of the two lines 2x - y + 4 = 0, and x - 2y + 5 = 0. Suppose that intersection occurs at the point $\displaystyle (x_{0},y_{0}).$ Then do the substitution $\displaystyle u=x-x_{0}$ and $\displaystyle v=y-y_{0}.$
The result of this substitution should result in a recognizeable type of DE. What do you get?