Question

Va rogg sa ma ajutati!
Multumesc frumos!
$c) \frac{1}{1+ \sqrt{2} }+ \frac{1}{ \sqrt{2} + \sqrt{3} }+..+ \frac{1}{ \sqrt{8}- \sqrt{9} }$.

Answer 1

Daca rationalizezi ai
(1-√2)/(-1) +(√2-√3)/(-1)+............+(√8-√9)/(-1)=
-1+√2-√2+√3-.........................-√8+√9=
simplificand
-1+√9=-1+3=2