What is the simplified form of?

Answer:
[tex] - 2 \sqrt{7} [/tex]
Step-by-step explanation:
[tex]3\sqrt{7} - 5\sqrt{7} = - 2 \sqrt{7} [/tex]
We subtract 3 and 5 and not the numbers under the radical.
The number under the radical can be changed if multiplied or divided.
3-5=-2 or
-5+3=-2
It's like having 5 dollar debt and then paying 3 dollars, you still have to pay those 2 dollars left.
Hope this helps ;) ❤❤❤