化简x+3y分之x-y÷x²y²分之x²+6xy+9y²-x+y分之2y

题目

化简x+3y分之x-y÷x²y²分之x²+6xy+9y²-x+y分之2y

答案

=(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）
=1