Question

simlify qn. no 3,4,5

Answer 1

(root 5-2)
using identity (a2-b2)
(root5)2 -2*2root5*2+(2)2
=5-4root5+4
=9-4root5

Answer 2

$\sqrt{45 } - \sqrt{180 } \\ 3 \sqrt{5 } - 6 \sqrt{5}$
-3√5