real numbers, question 10, grade 9

11/07/2016 Grade 9 951

10)

Given :  x=\frac{1}{{3-2\sqrt 2}} and  y=\frac{1}{{3+2\sqrt 2}}

  1. Calculate : x+y and x-y.
  2. Deduce that  {x^2}-{y^2}=24\sqrt 2