Factorise $x^{2} + y - xy - x$.

Factorise $x^{2} + y - xy - x$.
  1. $(x - 1)(x - y)$
  2. $(x + 1)(x - y)$
  3. $(x - 1)(x + y)$
  4. $(x - y)(x + 1)$

Solution

Rearrange: $x^{2} - xy - x + y = x(x-y) - 1(x-y) = (x-1)(x-y)$.

Asked in: IMO

Practice more FACTORISATION questions on Aicharya