Simplify: 15−2+15+2\frac{1}{\sqrt{5}-2} + \frac{1}{\sqrt{5}+2}5−21+5+21 A2√5 B√6 C√5 D2√6 Show answer & explanationCorrect answer: AExplanation15−2+15+2=(5+2)+(5−2)(5−2)(5+2)=5+2+5−25−4=251=25\frac{1}{\sqrt{5}-2} + \frac{1}{\sqrt{5}+2}\\ = \frac{(\sqrt{5}+2) + (\sqrt{5}-2)}{(\sqrt{5}-2)(\sqrt{5}+2)}\\ = \frac{\sqrt{5}+2+\sqrt{5}-2}{5-4}\\ = \frac{2\sqrt{5}}{1}\\ = 2\sqrt{5}5−21+5+21=(5−2)(5+2)(5+2)+(5−2)=5−45+2+5−2=125=25