Question:
Solve : (x + y) (dx – dy) = dx + dy. [Hint: Substitute x + y = z after separating dx and dy]
Solution:
Given differential equation, (x + y) (dx – dy) = dx + dy
(x + y) dx – (x – y) dy = dx + dy
– (x + y) dy – dy = dx – (x + y) dx
– (x + y + 1) dy = – (x + y – 1) dx
