Can you help me with this math?

Question

8: 4/ sqrt 3

9: sqrt 2/ sqrt 5

10: 2/2+ sqrt 2

11: 2/5- sqrt 3

12: sqrt 3/ sqrt 12- sqrt 5

13: 7/ sqrt 6-5

14: 7/5-sqrt 11

15: 6x/5x- sqrt 7

Answer 1

find the sqaure root of the first number than the square root of the next and divide ! its extremely simple

www.calculator.com is a great site for all those things !

Answer 2

8: 4/ sqrt 3= 4√3/3

9: sqrt 2/ sqrt 5=(√10)/5

10: 2/(2+ sqrt 2)= 2/(2+√2) * (2-√2)/(2-√2)=

2(2-√2)/(4-2)= 2-√2

11: 2/(5- sqrt 3)= 2/(5-√3) * (5+√3)/(5+√3)=

2(5+√3)/(25-3)=(5+√3)/11

12: sqrt 3/ (sqrt 12- sqrt 5)=

√3/(√12-√5) * (√12+√5)/(√12+√5)=

√3(√12+√5)/(12-5)=(√36+√15)/7=

(6-√15)/7

13: 7/ (sqrt 6-5)= 7/(√6-5)*(√6+5)/(√6+5)=

7(√6+5)/(6-25)= (7√6+35)/(-19)

14: 7/(5-sqrt 11)= 7/(5-√11)*(5+√11)/(5+√11)=

7(5+√11)/(25-11)=(5+√11)/2

15: 6x/(5x- sqrt 7)=6x/(5x-√7)*(5x+√7)/(5x+√7)=

6x(5x+√7)/(25x^2-7)