《乘法公式》练习题(一)
一、填空题
1.(a +b )(a -b )=_____,
2.(x -1)(x +1)=_____, (2a +b )(2a -b )=_____, (31x -y )(3
1x +y )=_____. 3.(x +4)(-x +4)=_____, (x +3y )(_____)=9y 2-x 2, (-m -n )(_____)=m 2-n 2
4.98×102=(_____)(_____)=( )2-( )2=_____.
5.-(2x 2+3y )(3y -2x 2)=_____.
6.(a -b )(a +b )(a 2+b 2)=_____.
7.(_____-4b )(_____+4b )=9a 2-16b 2, (_____-2x )(_____-2x )=4x 2-25y 2
8.(xy -z )(z +xy )=_____, (65x -0.7y )(65x +0.7y )=_____. 9.(41x +y 2)(_____)=y 4-16
1x 2 10.观察下列各式:
(x -1)(x +1)=x 2-1 (x -1)(x 2+x +1)=x 3-1 (x -1)(x 3+x 2+x +1)=x 4-1 根据前面各式的规律可得 (x -1)(x n +x n -1+…+x +1)=_____.
二、选择题
11.下列多项式乘法,能用平方差公式进行计算的是( )
A.(x +y )(-x -y )
B.(2x +3y )(2x -3z )
C.(-a -b )(a -b )
D.(m -n )(n -m )
12.下列计算正确的是( )
A.(2x +3)(2x -3)=2x 2-9
B.(x +4)(x -4)=x 2-4
C.(5+x )(x -6)=x 2-30
D.(-1+4b )(-1-4b )=1-16b 2
13.下列多项式乘法,不能用平方差公式计算的是( )
A.(-a -b )(-b +a )
B.(xy +z )(xy -z )
C.(-2a -b )(2a +b )
D.(0.5x -y )(-y -0.5x )
14.(4x 2-5y )需乘以下列哪个式子,才能使用平方差公式进行计算( )
A.-4x 2-5y
B.-4x 2+5y
C.(4x 2-5y )2
D.(4x +5y )2
15.a 4+(1-a )(1+a )(1+a 2)的计算结果是( )
A.-1
B.1
C.2a 4-1
D.1-2a 4 16.下列各式运算结果是x 2-25y 2的是( )
A.(x +5y )(-x +5y )
B.(-x -5y )(-x +5y )
C.(x -y )(x +25y )
D.(x -5y )(5y -x )
三、解答题
17. 1.03×0.97 18.(-2x 2+5)(-2x 2-5) 19.a (a -5)-(a +6)(a -6)
20.(2x -3y )(3y +2x )-(4y -3x )(3x +4y ) 21.(31x +y )(31x -y )(9
1x 2+y 2) 22.(x +y )(x -y )-x (x +y ) 23. 3(2x +1)(2x -1)-2(3x +2)(2-3x )
24.9982-4 25.2003×2001-20022
《乘法公式》练习题(二)
一. 判断对错
1.222)(b a b a +=+--( ) 2.2222)(y xy x y x +-=----( )
3.2222)(b ab a b a ++=----( ) 4.2229122)32(y xy x y x +-=-( )
5.2294)32)(32(y x y x y x -=-+( )
二.填空
6______________)3)(32(=-+y x y x ; 7._______________)52(2=+y x ;
8.______________)23)(32(=--y x y x 9.______________)32)(64(=-+y x y x ;10________________)22
1(2=-y x 11.____________)9)(3)(3(2=++-x x x ;
12.___________1)12)(12(=+-+x x ; 13. 4))(________2(2-=+x x ;
14._____________)3)(3()2)(1(=+---+x x x x ;
15.____________)2()12(22=+--x x ;16.224)__________)(__2(y x y x -=-+;
17.______________)1)(1)(1)(1(42=++-+x x x x ;
18.下列多项式乘法中不能用平方差公式计算的是( )