(√ 5 - √ 3)/ (√ 5 + √ 3) is equal to?

(√5 - √3)/ (√5 + √3)
= (√5 - √3) / (√5 + √3)
= (√5 - √3)² / (5 - 3)
= (5 + 3 - 2√5 x 3) / 2
= 2 (4 - √15) / 2
= (4 - √15)