I need help on this question!!

Answer:
29
Step-by-step explanation:
We can use the formula (a+b)(a-b)=a^2-b^2 to help us simplify this problem.
[tex](6-\sqrt{7})(6+\sqrt{7})\\= 6^2-(\sqrt{7})^2\\= 36-7\\=29[/tex]
I hope this helps! Please comment if you have any questions.