yang ini kak 19 sampai 25 pake cara??

19) ( 5 / 2- √3 ) × ( 2+√3 / 2+√3 )

= 5 × ( 2+√3 )
--------------------
( 2- √3 × 2+√3 )

= 5 ( 2 + √3 )
--------------------
( 4 - 3 )

= 5 ( 2 + √3 )
--------------------
1

= 5 ( 2 + √3)

= 10 + 5√3 ( C )

20) ( 7 / √5+√3 ) × ( √5-√3 / √5-√3 )

= 7 × ( √5 - √3 )
--------------------------------
( √5+√3 ) × ( √5 - √3)

= 7 ( √5 - √3 )
----------------------
5 - 3

= 7 ( √5 - √3)
----------------------
2

= 7/2 (√5 - √3) ( A )

21) ( 6 / √7-√11) × (√7+√11 / √7+√11 )

= 6 × ( √7 + √11 )
---------------------------------
( √7 - √11) × ( √7 + √11)

= 6 ( √7 + √11 )
------------------------
7 - 11

= 6 ( √7 + √11)
----------------------
- 4

= - 3/2 ( √7 + √11 ) ( B )

22) ( 13 / 5+2√3 ) × ( 5-2√3 / 5-2√3 )

= 13 × ( 5 - 2√3 )
---------------------------------
( 5 + 2√3 ) × ( 5 - 2√3)

= 13 ( 5 - 2√3 )
----------------------
25 - 12

= 13 ( 5 - 2√3 )
-----------------------
13

= 5 - 2√3 ( B )

23) ( ³√2 )^ x+10 = 8

(2^⅓)^x+10 = 2³

=> (⅓) x + 10 = 3

=> ⅓x + 10/3 = 3

=> ⅓x = 3 - 10/3

=> ⅓x = 9/3 - 10/3

=> ⅓x = - ⅓

=> x = - 1 ( C )

24) 2^x • (2^x+1)^x • (2^x)^1-x = 8

2^x • 2^x²+x • 2^x-x² = 2³

=> x + (x² + x) + (x - x²) = 3

=> x + x + x + x² - x² = 3

=> 3x = 3

=> x = 1 = 2^0 ( A )

25) √2 + √3 - ( -2√5 + √3 )

= √2 + 2√5 + √3 - √3

= √2 + 2√5 ( A )