Let us solv

p (x + y) = q (x – y) = 2pq

⇒ px + py = 2pq … (1)

⇒ qx – qy = 2pq … (2)

Expressing x of equation (1) in terms of y,

⇒ px + py = 2pq

⇒ px = 2pq – py

⇒ x = 2q – y … (3)

Substituting (3) in (2),

⇒ q (2q – y) – qy = 2pq

⇒ q (2q – y – y) = 2pq

⇒ 2q – 2y = 2p

⇒ 2 (q – y) = 2p

⇒ q – y = p

∴ y = p – q

Substituting y value in (3),

⇒ x = 2q – y

⇒ x = 2q – (p – q)

∴ x = 3q – p

∴ By solving, we get x = 3q – p and y = p – q.