Question

Is the number (3-√7) (3+√7) rational or irrational

Answer 1

(3-√7) (3+√7) 

it is in the ( a+b) (a-b ) which is equal to $a^{2} - b^{2}$

9 - 7 

= 2 

so it is rational 

Answer 2

,, it is in the a + b bracket a minus b which is equal to a square minus b square is equal to 9 - 7 is equal to 2 so it is rational number