约分①（x+y）y／xy²③x²+xy／(x+y)²④x²-y²／(x-y)²求正确答案过程

约分①（x+y）y／xy²③x²+xy／(x+y)²④x²-y²／(x-y)²求正确答案过程
约分①（x+y）y／xy²③x²+xy／(x+y)²④x²-y²／(x-y)²求正确答案过程

约分①（x+y）y／xy²③x²+xy／(x+y)²④x²-y²／(x-y)²求正确答案过程
①（x+y）y／xy²=x+y/xy
③ x²+xy／(x+y)²=x（x+y）/(x+y)²=x/x+y
④ x²-y²／(x-y)²=(x+y)(x-y)/(x-y)²=x+y/(x-y)

(x+y)y/x*y*y=(x+y)/xy
x*x+x*y/(x+y)(x+y)=x*(x+y)/(x+y)(x+y)=x/(x+y)
x^2-y^2/(x-y)^2=(x-y)(x+y)/(x-y)^2=(x+y)/(x-y)