A square garden of side $a$ has a square pond of side $b$ ($a > b$) at one corner. The remaining area is

A square garden of side $a$ has a square pond of side $b$ ($a > b$) at one corner. The remaining area is
  1. $(a - b)(a + b)$
  2. $(a - b)^{2}$
  3. $(a + b)^{2}$
  4. $a^{2} - 2ab + b^{2}$

Solution

Remaining area $= a^{2} - b^{2} = (a-b)(a+b)$.

Asked in: IMO

Practice more FACTORISATION questions on Aicharya