-------------------------------------------------www.ddhw.com 设 a = bwww.ddhw.com 方程两边乘 a a2 = abwww.ddhw.com 方程两边减 b2 a2 – b2 = ab – b2www.ddhw.com 方程两边因式分解 (a + b)(a – b) = b(a – b)www.ddhw.com 方程两边消去公因子 (a +b) = bwww.ddhw.com 代入假设 a = b 则 b + b = bwww.ddhw.com 即 2b = bwww.ddhw.com 或 2 = 1 哇!!!www.ddhw.com ------------------------------------------------ 怎么会?为什么? www.ddhw.com
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