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1.(a-b)/(a+b)×(a^4-a²b²)/a²-ab2.(x²+3x)/(x²+2x)-(x²-4)/(x²+4x+4)

题目详情
1.(a-b)/(a+b)×(a^4-a²b²)/a²-ab
2.(x²+3x)/(x²+2x)-(x²-4)/(x²+4x+4)
▼优质解答
答案和解析
(a-b)/(a+b)×(a^4-a²b²)/a²-ab
=(a-b)/(a+b)*a²(a²-b²)/a²-ab
=(a-b)/(a+b)*(a+b)(a-b)-ab
=(a-b)²-ab
=a²-3ab+b²
(x²+3x)/(x²+2x)-(x²-4)/(x²+4x+4)
=x(x+3)/(x(x+2))-(x+2)(x-2)/(x+2)²
=(x+3)/(x+2)-(x-2)/(x+2)
=(x+3-(x-2))/(x+2)
=5/(x+2)