问题标题:
快啊!急需!初二数学:运用平方差公式计算(附详细答案,讲解.谢谢)运用平方差公式计算下面各题:(x-1/3)(x^2+1/9)(x+1/3)(2x-1/3)(-1/3-2x)(-1/9-4x^2)(2x+3y-1)(2x-3y+1)2011^2-2010×2012
问题描述:
快啊!急需!初二数学:运用平方差公式计算
(附详细答案,讲解.谢谢)
运用平方差公式计算下面各题:
(x-1/3)(x^2+1/9)(x+1/3)
(2x-1/3)(-1/3-2x)(-1/9-4x^2)
(2x+3y-1)(2x-3y+1)
2011^2-2010×2012
邵文远回答:
(x-1/3)(x^2+1/9)(x+1/3)
=(x^2-1/9)(x^2+1/9)
=(x^4-1/81)
(2x-1/3)(-1/3-2x)(-1/9-4x^2)
=(4x^2-1/9)(4x^2+1/9)
=16x^4-1/81
(2x+3y-1)(2x-3y+1)
=(2x)²-(3y-1)²
=4x²-(3y-1)²
2011^2-2010×2012
=2011^2-(2011-1)×(2011+1)
=2011^2-(2011^2-1)
=1
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