Answer:
-6[tex]\sqrt{7}[/tex]
Step-by-step explanation:
([tex]\sqrt{7}[/tex] - 7) · (1 + [tex]\sqrt{7}[/tex])
= [tex]\sqrt{7}[/tex] + [tex]\sqrt{49[/tex] - 7 - 7[tex]\sqrt{7}[/tex]
= [tex]\sqrt{7}[/tex] + [tex]\sqrt{7^{2} }[/tex] - 7 - 7[tex]\sqrt{7}[/tex]
= [tex]\sqrt{7}[/tex] + 7 - 7 - 7[tex]\sqrt{7}[/tex]
= [tex]\sqrt{7}[/tex] - 7[tex]\sqrt{7}[/tex]
= -6[tex]\sqrt{7}[/tex]
So, the answer is -6[tex]\sqrt{7}[/tex].
