simple multiple choice question?

Alright, lets get started.
The given expression is :
[tex]5\sqrt{7} +\sqrt{7}-2 \sqrt{7}[/tex]
We are asked to simplify.
Each term is having [tex]\sqrt{7}[/tex] in it.
So, taking [tex]\sqrt{7}[/tex] common factor out, it will be
[tex]5\sqrt{7} +\sqrt{7}-2 \sqrt{7}[/tex]
[tex]\sqrt{7} (5+1-2)[/tex]
[tex]\sqrt{7} (6-2)[/tex]
[tex]\sqrt{7} *4[/tex]
[tex]4\sqrt{7}[/tex]
So, the answer is [tex]4\sqrt{7}[/tex] : Answer
Hope it will help :)