Two Difference/Sum of Squares Problems

[artshep]

Hello,

I'm having some trouble applying difference/sum of square rules when there are fractions involved. If anyone can take a look at the two problems below and let me know how to approach them, I would appreciate it.

Problem #1 ****

If n is positive, which of the following is equal to 1/(SQRT(n+1) - SQRT(n)) ?

A. 1
B. SQRT (2n+1)
C. SQRT(n+1) / SQRT(n)
D. SQRT(n+1) - SQRT(n)
E. SQRT(n+1) + SQRT(n)


Problem #2 ****

(2 + SQRT 5) / (2 - SQRT 5) = ??


Thanks for any help...

Artis

 

[pka]

\(\displaystyle \L\frac{1}{{\sqrt {n + 1} - \sqrt n }}\frac{{\sqrt {n + 1} + \sqrt n }}{{\sqrt {n + 1} + \sqrt n }}\)