平方差公式分解因式专项练习题
平方差公式分解因式专项练习题
1、分解因式
(1)x 2-y 2 (2)-x 2+y 2 (3)64-a 2 (4)4x 2-9y 2
4(5) 36-25x 2 (6) 16a 2-9b 2 (7)92-0.01n 2
(8)(x +p ) 2-(x +q ) 2 (9)16(m -n ) 2-9(m +n ) 2 (10)9x 2-(x -2y ) 2
(9)4a 2-16 (10)a 5-a 3 (11)x 4-y 4 (12)32a 3-50ab 2
2、判断正误
(1)-x 2-y 2=(x +y )(x -y ) ( ) (2)9-25a 2=(9+25a )(9-25a ) ( )
(3)-4a 2+9b 2=(-2a +3b )(-2a -3b ) ( )
3、分解因式
(1)4a 2-(b +c ) 2 (2)(3m +2n ) 2-(m -n ) 2
(3)(4x -3y ) 2-16y 2 (4)-4(x +2y ) 2+9(2x -y ) 2
4、判断:下列各式能不能写成平方差的形式(能画“√”,并分解,不能的画“×”)
(1)x 2+64 ( ); (2)-x 2-4y 2 ( )
1(3)9x 2-16y 4 ( ); (4)-4x 6+9n 2 ( )
(5)-9x 2-(-y ) 2 ( ); (6)-9x 2+(-y ) 2 ( )
(7)(-9x ) 2-y 2 ( ); (8)(-9x ) 2-(-y ) 2 ( )
5、 下列各式中,能用平方差公式分解因式的是 ( )
A . -a 2+b 2 B . -a 2-b 2 C . a 2+b 2 D. a 3-b 3
6、 (x +1) 2-y 2分解因式应是 ( )
A . (x +1-y )(x +1+y ) B . (x +1+y )(x -1+y )
C . (x +1-y )(x -1-y ) D . (x +1+y )(x -1-y )
7. 填空(把下列各式因式分解)
(1)1-p 2=____________ (2)49c 2-36=________________
1
24m n 22(3)-=___________ (4)-0. 25a m +9=______________ 9256
(5)4-x 2n =______________ (6)(a +b ) 2-1=__________________
8. 把下列各式分解因式
4(1) 4x 2-9y 2 (2) 0. 81a 2-16b 2 (3) m 2-0. 012 9
(4) 8a 3-2a (a +1) 2 (5) -(b -c )2+4a 2 (6)1-16a 4b 4
(7)(3m +2n )2-(m -n )2 (8)4z 2-(x +y )2 (9) 4(x -y )2-25(x +y )2
(10)(a +b +c )2-(a +b -c )2 (11)(a +b )3-4(a +b )
9. 运用简便方法计算
(1)20072-49 (2)1. 222⨯9-1. 332⨯4
1125(3)已知x =75,y =22, 求(x +y ) 2-(x -y ) 2的值.
10、(1) 36-25x 2 (2) 16a2-9b 2
11、填空
1、分解因式:(1)a 2-9;(2)x 3-x =
(3)4a 2-9b 2(4)-25a 2y 4+16b 2=
(5)3a 3-75a (6)9a 3b -ab =
12、分解因式:(1)x 4-y 4(2)m 2-4m 2n 2=
13、分解因式:x 4-(5x +3) 2=
2
14、分解因式:25-(2n +1) 2=
15、若a +b =1004, a -b =2,则代数式a 2-b 2的值是
16、分解因式:81x 4-y 4=
117、分解因式:-9a 2+= 9
118、已知x 2-y 2=-1 , x+y=,则x -y= . 2
19、把下列各式分解因式:
1(1) 36-x 2 (2) a2-b 2 (3) x2-16y 2
9
(4) x2y 2-z 2 (5) (x+2)2-9 (6)(x+a)2-(y+b)2
(7) 25(a+b)2-4(a-b) 2 (8) 0.25(x+y)2-0.81(x-y) 2
(9)(a +b +c ) 2-(a +b -c ) 2 (10)-(a +2) 2+16(a -1) 2
20、计算:
21、已知:4m+n=90,2m -3n=10,求(m+2n)2-(3m-n) 2的值。
22.利用因式分解计算:
(1)492-512;
3 1001 222003-2001 1⎫⎛1⎫⎛1⎛(2) 1-2⎪1-2⎪1-2⎝2⎭⎝3⎭⎝41⎫⎛1⎫⎫⎛ 1-1-. ⎪ 2⎪2⎪⎭⎝9⎭⎝10⎭