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x/x-2-1/x+28a/a²-b²+b/ab+b²
题目详情
x/x-2-1/x+2
8a/a²-b² + b/ab+b²
8a/a²-b² + b/ab+b²
▼优质解答
答案和解析
x/(x-2) -1/(x+2) 最简公分母是(x-2)(x+2)
=x(x+2)/[(x-2)(x+2)] -(x-2)/[(x-2)(x+2)]
=[x(x+2)-(x-2)]/[(x-2)(x+2)]
=(x²+2x-x+2)/[(x-2)(x+2)]
=(x²+x+2)/[(x-2)(x+2)]
8a/(a²-b²) + b/(ab+b²)
=8a/[(a-b)(a+b)] +b/[b(a+b)] 最简公分母是b(a-b)(a+b)
=8ab/[b(a-b)(a+b)] +b(a-b)/[b(a-b)(a+b)]
=[8ab+b(a-b)]/[b(a-b)(a+b)]
=(8ab+ab-b²)/[b(a-b)(a+b)]
=(9ab-b²)/[b(a-b)(a+b)]
=b(9a-b)/[b(a-b)(a+b)]
=(9a-b)/[(a-b)(a+b)]
=x(x+2)/[(x-2)(x+2)] -(x-2)/[(x-2)(x+2)]
=[x(x+2)-(x-2)]/[(x-2)(x+2)]
=(x²+2x-x+2)/[(x-2)(x+2)]
=(x²+x+2)/[(x-2)(x+2)]
8a/(a²-b²) + b/(ab+b²)
=8a/[(a-b)(a+b)] +b/[b(a+b)] 最简公分母是b(a-b)(a+b)
=8ab/[b(a-b)(a+b)] +b(a-b)/[b(a-b)(a+b)]
=[8ab+b(a-b)]/[b(a-b)(a+b)]
=(8ab+ab-b²)/[b(a-b)(a+b)]
=(9ab-b²)/[b(a-b)(a+b)]
=b(9a-b)/[b(a-b)(a+b)]
=(9a-b)/[(a-b)(a+b)]
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