Answer:
2
Step-by-step explanation:
Apply Difference of Two Squares formula: [tex]\left(a+b\right)\left(a-b\right)=a^2-b^2[/tex]:
[tex]\implies (3+\sqrt{7} )(3-\sqrt{7} )=3^2-(\sqrt{7} )^2[/tex]
[tex]=9 - 7[/tex]
[tex]=2[/tex]
