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计算或化简:[(x-y)/(x+3y)]÷[(x²-y²)/(x²+6xy+9y²)]-(2y)/x+y

题目详情
计算或化简:[(x-y)/(x+3y)]÷[(x²-y²)/(x²+6xy+9y²)]-(2y)/x+y
▼优质解答
答案和解析
原式=[(x-y)/(x+3y)]×[(x+3y)²/(x+y)(x-y)]-2y/(x+y)
=(x+3y)/(x+y)-2y/(x+y)
=(x+3y-2y)/(x+y)
=(x+y)/(x+y)
=1