Question

Simplify sqrt 363 -3 sqrt 27

Answer 1

If you have 2 of the same factor in a square root you take them out but just write one.

Looking at $\sqrt{363}$
$\sqrt{363} = \sqrt{3*11*11} =11 \sqrt{3}$

Looking at $3 \sqrt{27}$
$3\sqrt{27}=3 \sqrt{3*3*3} = (3*3)\sqrt{3} =9 \sqrt{3}$

Put them back together:
$11 \sqrt{3} -9 \sqrt{3} =2 \sqrt{3}$