题目内容
(1)(3x+1)2(3x-1)2;
(2)(2m+3n)(2m-3n)-(3m-2n)(3m+2n);
(3)a(a+2)(a-2)-a3-1;
(4)(2x-3y-1)(2x+3y-1);
(5)1999×2001.
下列运算中,正确的是
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A.(a+5)(a-5)=a2-5
B.(3b+2)(3b-2)=3b2-4
C.(3m-2n)(-2n-3m)=4n2-9m2
D.(x+2)(x-3)=x2-6
A.(a+1)(2a-2) B.(2x-3)(-2x+3)
C.(2y-)(+2y) D.(3m-2n)(-3m-2n)