运用乘法公式计算,很简单的~~~1.(x+1)^2-(2x+3)(2x-3)2.(x-2y-z)(x+2y-z)3.2006*2008

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运用乘法公式计算,很简单的~~~
1.(x+1)^2-(2x+3)(2x-3)
2.(x-2y-z)(x+2y-z)
3.2006*2008

1.原式=x^2+2x+1-4x^2+9
=-3x^2+2x+10
2.原式=(x-z)^2-4y^2
=x^2-2xz+z^2-4y^2
=x^2-4y^2+z^2-2xz
3.原式=(2007-1)(2007+1)
=2007^2-1
=4028048

.(x+1)^2-(2x+3)(2x-3)=x^2 +2x+1-4X^2+6=-3x^2+2x+7
.(x-2y-z)(x+2y-z)=( (x-z)-2y )((x-z)+2y)=(x-z)^2-4y^2=x^2-2xz+z^2-4Y^2
2006*2008=(2007-1)(2007+1)=2007^2-1=68048

=x^2+2x+1-(4x^2-9)=-3x^2+2x+10
2 =(x-z)^2-4y^2=x^2-2xz+z^2-4y^2
3 =(2000+6)*(2000+8)=4028048