cara kerja 18-19 gimana?.... .... .... bantuin kak

8(3-√5)
------------------
(3+√5)(3-√5)

=8(3-√5)
-------------
9-5

=8(3-√5)
-------------
4
=2(3-√5)
=6-2√3

1(2-√5)
--------------------
(2-√5)×(2+√5)

=2+√5
--------------------
(2-√5)×(2+√5)

=2+√5
-----------
4-5

=2+√5
------------
-1

=-(2+√5)
=-2-√5