So choose one
2. Simplify (√x+√y)? +(√x-√y)? =2x+2y
3. Calculate √9-4√ 1/2+√8.
=3-2√+4√2
=3+2√2
4、a? b-b? a=ab(a-b)
=(3+2√2)(3-2√2)(3+2√2-3+2√2)
=(9-8)4√2
=4√2
Step 5 simplify
Original formula =a+2√a-a
=2√a
6、x? -2xy+y?
=(x-y)?
=(√7+√5)/2-(√7-√5)/2?
=7