Question

Find separate equations of lines represented by x² – y² + x + y = 0.

Answer 1

x² – y² + x + y = 0

∴ (x – y) (x + y) + (x + y) = 0

∴ (x + y) (x – y + 1) = 0

∴ Separate equations of the lines are x + y = 0 and x – y + 1 = 0.