How do you simplify #2sqrt2+4sqrt2#?
Just add the numbers in front of the roots, so it'll look like 6 times the square root of two,
As long as the number in the roots and the roots itself are the same, then you simplify using addition or subtraction. If it is multiplication. then you can multiply the two values, even if the number in the root is different. Don't multiply if the roots itself is different, like cube root and square root. Division is a whole 'nother topic.
a√x +b√x = (a+b)√x
a√x -b√x = (a-b)√x