1.（x+2y）/(x+y)*xy/(x+2y)÷[(x+y)/xy]
=xy/(x+y)÷[(x+y)/xy]
=x²y²/(x+y)²
2.(a+b)²/(ab)²÷(b²-a²)/a²b²
=(a+b)²÷[(b+a)(b-a)]
=(a+b)/(b-a)
3.
原式=3x³/8y +x³/4y^5
4.原式=2(a+b)/[3(a-b)]-ab/(a-b)(a+b)
=[2(a+b)²-3ab]/[3(a-b)(a+b)]
=[2a²+ab+b²]/[3(a-b)(a+b)]
1.（x+2y）/(x+y)*xy/(x+2y)÷[(x+y)/xy]
=xy/(x+y)÷[(x+y)/xy]
=x²y²/(x+y)²
2.(a+b)²/(ab)²÷(b²-a²)/a²b²
=(a+b)²÷[(b+a)(b-a)]
=(a+b)/(b-a)
3.
原式=3x³/8y +x³/4y^5
4.原式=2(a+b)/[3(a-b)]-ab/(a-b)(a+b)
=[2(a+b)²-3ab]/[3(a-b)(a+b)]
=[2a²+ab+b²]/[3(a-b)(a+b)]