实用标准文档大全乘法公式巩固专练一、填空题1.直接写出结果:(1)(x+2)(x-2)=_______;(2)(2x+5y)(2x-5y)=______;(3)(x-ab)(x+ab)=_______;(4)(12+b2)(b2-12)=______.2.直接写出结果:(1)(x+5)2=_______;(2)(3m+2n)2=_______;(3)(x-3y)2=_______;(4)2)32(ba=_______;(5)(-x+y)2=______;(6)(-x-y)2=______.3.先观察、再计算:(1)(x+y)(x-y)=______;(2)(y+x)(x-y)=______;(3)(y-x)(y+x)=______;(4)(x+y)(-y+x)=______;(5)(x-y)(-x-y)=______;(6)(-x-y)(-x+y)=______.4.若9x2+4y2=(3x+2y)2+M,则M=______.二、选择题1.下列各多项式相乘,可以用平方差公式的有().①(-2ab+5x)(5x+2ab)②(ax-y)(-ax-y)③(-ab-c)(ab-c)④(m+n)(-m-n)(A)4个(B)3个(C)2个(D)1个2.若x+y=6,x-y=5,则x2-y2等于().(A)11(B)15(C)30(D)603.下列计算正确的是().(A)(5-m)(5+m)=m2-25(B)(1-3m)(1+3m)=1-3m2(C)(-4-3n)(-4+3n)=-9n2+16(D)(2ab-n)(2ab+n)=4ab2-n24.下列多项式不是完全平方式的是().(A)x2-4x-4(B)mm241(C)9a2+6ab+b2(D)4t2+12t+95.下列等式能够成立的是().(A)(a-b)2=(-a-b)2(B)(x-y)2=x2-y2(C)(m-n)2=(n-m)2