15.2 乘法公式同步练习(一)
(一)基本训练,巩固旧知
1.计算:
(1)(x+3)(x-3)= (2)(m+2)(m-2)=
(3)(2x+1)(2x-1)=
2.用平方差公式计算:
(1) (a+3b)(a-3b) (2) (1+2y)(1-2y)
=
=
(3) (4x-5)(4x+5) (4) ( 1
2 +2m)( 1
2 -2m)
3.用平方差公式计算:
(1) (3b+a)(a-3b) (2) (3m-4n)(4n+3m)
(3) (3+2a)(-3+2a) (4) (7-2a)(-7-2a)
4.计算:
(y+2)(y-2)-(y-1)(y+5)
15.2 乘法公式同步练习(二)
(一)基本训练,巩固旧知
1.填空:两个数的和乘以这两个数的差,等于这两个数的 ,即
(a+b)(a-b)= ,这个公式叫做 公式.
2.用平方差公式计算
(1) (-m+5n)(-m-5n) (2) (3x-1)(3x+1)
= =
= =
(3) (y+3x)(3x-y) (4) (-2+ab)(2+ab)
= =
= =
= =
3.判断正误:对的画“√”,错的画“×”.
(1)(a-b)(a+b)=a2-b2; ( ) (2)(b+a)(a-b)=a2-b2; ( )
(3)(b+a)(-b+a)=a2-b2; ( ) (4)(b-a)(a+b)=a2-b2; ( )
(5)(a-b)(a-b)=a2-b2. ( )
4.用多项式乘多项式法则计算:
(1) (a+b)2 (2) (a-b)2
=(a+b)(a+b) =(a-b)(a-b)
= =
= =
5.运用完全平方公式计算:
(1) (x+6)2 (2) (y-5)2
= =
= =
(3) (-2x+5)2 (4) ( 3
4 x- 2
3 y)2
= =
= =
6.计算:
(x+1)(x-3)-(x+2)2+(x+2)(x-2)
=
=
=
7.选做题:如图,利用图形你能得到公式
(a+b)2=a2+2ab+b2 吗?
b
a
b
a
15.2 乘法公式同步练习(三)
(一)基本训练,巩固旧知
1.填空:
(1)平方差公式(a+b)(a-b)= ;
(2)完全平方公式(a+b)2= ,(a-b)2= .
2.运用公式计算:
(1) (2x-3)2 (2) (-2x+3y)(-2x-3y)
= =
= =
(3) ( 1
2 m-3)( 1
2 m+3) (4) ( 1
3 x+6y)2
= =
= =
3.判断正误:对的画“√”,错的画“×”.
(1)(a+b)2=a2+b2; ( ) (2)(a-b)2=a2-b2; ( )
(3)(a+b)2=(-a-b)2; ( )(4)(a-b)2=(b-a)2. ( )
4.去括号:
(1)(a+b)-c= (2)-(a-b)+c=
(3)a+(b-c)= (4)a-(b+c)=
5.填空:
(1)a+b+c=( )+c; (2)a-b+c=( )+c;
(3)-a+b-c=-( )-c; (4)-a-b+c=-( )+c;
(5)a+b-c=a+( ) (6)a-b+c=a-( );
(7)a-b-c=a-( ); (8)a+b+c=a-( ).
6.运用乘法公式计算:
(1) (a+2b-1)2 (2) (2x+y+z)(2x-y-z)
= =
= =
= =
= =