Question

1.x方y-xy方分之x方-2xy+y方加上xy分之x方-y方 2.(2b分之-3ac）方除以（-9ac）方

3.a方-4a+4 分之 a方-1 除以（a+1) 乘以 a-1 分之 a+2

Answer 1

解1题：
原式=(x²-2xy+y²)/(x²y-xy²)+(x²-y²)/(xy)
=(x-y)²/[xy(x-y)]+(x²-y²)/(xy)
=(x-y)/(xy)+(x²-y²)/(xy)
=[(x-y)+(x²-y²)]/(xy)
=(x-y)(x+y+1)/(xy)

解2题：
原式=[-3ac/(2b)]²÷(-9ac)²
=(-3ac)²/(2b)²×1/(-9ac)²
=9a²c²/(4b²)×1/(81a²c²)
=1/(36b²)

解3题：
原式=[(a²-1)/(a²-4a+4)]÷(a+1)×[(a+2)/(a-1)]
=[(a+1)(a-1)/(a-2)²]×[1/(a+1)]×[(a+2)/(a-1)]
=(a+2)/(a-2)²