If the formulas under the root sign are opposite to each other, then both formulas under the root sign are equal to 0.

For example: 2-x=x-2=0, then x=2.

Y=- 1。

Then √x-6y=√(2+6)=2√2.

Question 2: (a-√ 2)? +(b+√3)？ =0, then a = √ 2 and b =-√ 3.

Then a/(b- 1)=√2/2-√6/2.

Then √(a? +4b？ )=√ 14

Question 3: X? - 16= 16-x？ =0, then x=-4(x≠4), then y=- 1/4.

Then √xy= 1