Question

which of the following pairs of numbers gives an irrational number as their difference.

3√7 , 3√7

2, -2

3√2, -3√2

√8, √8

Answer 1

Hiya 

Its simple 

Lets check 

1) 3√7  - 3√7    = 0 ( rational ) 

2) 2-(-2)           = 4 ( rational ) 

3) 3√2 -(-3√2 ) = 6√2 ( irrational ) 

4) √8 - √8 = 0 ( rational ) 

So third  the difference of 3√2 and -3√2 will gives us an irrational number

Answer 2

1) 3 root7 - 3 root7 = 0 , which is a rational number
2) 2 - (-2) = 2+2 = 4 , which is a rational number
3) 3 root2 - ( -3root2) = 3root2 + 3root2 = 6 root2, which ia an irrational number
4) root8 - root8 = 0, which is an irrational number
therefore, 3 root2, -3root2 gives an irrational number as their difference