Question

这两道题该怎么化简呢，请回答者不要省略过程，谢谢

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Answer 1

解第1题
原式=(√y)/(√x+√y)-[√(xy)-(x√y)/(√x+√y)]÷√(xy)
=(√y)/(√x+√y)-[√(xy)×1/√(xy)-(x√y)/(√x+√y)×1/√(xy)]
=(√y)/(√x+√y)-[1-√x×√(xy)/(√x+√y)×1/√(xy)]
=(√y)/(√x+√y)-[1-(√x)/(√x+√y)]
=(√y)/(√x+√y)+(√x)/(√x+√y)-1
=(√x+√y)/(√x+√y)-1
=1-1
=0

解第2题：
a=1/√3=(√3)/3﹤1
原式=(1-2a+a²)/(a-1)-[√(a²-2a+1)]/(a²-a)
=(a-1)²/(a-1)-[√(a-1)²]/[a(a-1)]
=a-1-|a-1|/[a(a-1)]
=a-1+(a-1)/[a(a-1)]
=a-1+(1/a)
当a=(√3)/3时
原式=(√3)/3-1+√3
=(√3-3+3√3)/3
=(4√3-3)/3