Mathematics Radical Numbers Problem

Question

If,

$$\frac{\sqrt 5+1}{\sqrt 2-1} = x $$

then,

$$\frac{\sqrt 5-1}{\sqrt 2+1} = ? $$

Answer 1

Let $y=\frac{\sqrt 5-1}{\sqrt 2+1}$

$$\implies xy=\dfrac{5-1}{2-1}=?$$

Answer 2

Hint: Simplify the product of the two expressions.