2021年度苏科版七年级数学下册《9.5多项式的因式分解》综合能力提升训练(附答案)
1.因式分解
(1)(x﹣y)3﹣4(x﹣y)
(2)﹣2x3+12x2﹣18x
2.因式分解:
(1)m3﹣9m
(2)(x﹣y)2﹣(x+y)(x﹣y)
3.将下列各式分解因式:
(1)(p﹣4)(p+1)+3p;
(2)4xy2﹣4x2y﹣y3
4.分解因式
(1)8a3b2+12ab3c
(2)a3﹣2a2+a
(3)(2x+y)2﹣(x+2y)2
5.分解因式:
(1)ax+bx
(2)x4﹣y4
(3)(a+b)2﹣4a(a+b)+4a2
6.因式分解:
(1)2x3﹣8x;
(2)(x+3y)2﹣12xy
7.因式分解:
(1)(x﹣1)(x﹣3)+1
(2)a2(x﹣y)+4b2(y﹣x)
8.因式分解:
(1)x3y﹣xy3;
(2)(x+2)(x+4)+x2﹣4.
9.分解因式:
(1)3x3﹣27x
(2)(y2+1)2﹣4y2
10.因式分解:
(1)﹣2x2﹣8y2+8xy;
(2)(p+q)2﹣(p﹣q)2
11.分解因式
(1)m3(x﹣2)+m(2﹣x)
(2)4a(b﹣a)﹣b2
12.因式分解:
(1)x2﹣2x+1;
(2)a2(1﹣m)+4(m﹣1);
(3)(x﹣y)2﹣4(x﹣y﹣1).
13.因式分解:
(1)a3﹣a;
(2)4ab2﹣4a2b﹣b3;
(3)a2(x﹣y)﹣9b2(x﹣y);
(4)(y2﹣1)2+6
(1﹣y2)+9.
14.将下列各式因式分解:
(1)3ax2﹣6axy+3ay2;
(2)9(a+b)2﹣(a﹣b)2.
15.因式分解:
(1)2x2﹣50;
(2)a2(a﹣b)﹣b2(a﹣b).
16.把下列各式分解因式:
(1)4a2﹣16;
(2)(y﹣1)2﹣10(y﹣1)+25;
(3)(x+2)(x+4)+1.
17.因式分解:
(1)3ab3﹣30a2b2+75a3b;
(2)a2(x﹣y)+16(y﹣x);
(3)(x2+y2)2﹣4x2y2.
18.因式分解:
(1)ab2﹣3a2b+ab;
(2)xy2﹣x;
(3)3x2﹣6x+3;
(4)(4m2+9)2﹣144m2.
19.因式分解:
(1)m2﹣16;
(2)x2(2a﹣b)﹣y2(2a﹣b);
(3)y2﹣6y+9;
(4)x4﹣8x2y2+16y4.
20.分解因式:
(1)(x+2y)2﹣y2;
(2)m2(m﹣1)﹣4(1﹣m)2.
21.把下列各式分解因式:
(1)4a2﹣16;
(2)(y﹣1)2﹣10(y﹣1)+25.
22.把下列各式分解因式:
(1)2a2﹣12ab+18b2;
(2)(x2﹣2y)2﹣(1﹣2y)2.
23.把下列各式因式分解
(1)﹣4a2x2+8ax﹣4;
(2)9(2a+3b)2﹣4(3a﹣2b)2.
24.分解因式:(注意使用正确的解答格式)
(1)3ax3﹣30ax2+75ax
(2)(4m2+9)2﹣144m2
(3)﹣5a2b﹣10a2b3+15a4b
(4)5a3b(a﹣b)3﹣15a4b3(b﹣a)2
(5)3x2+2x+
(6)(8a2+b2)2﹣(a2+8b2)2
(7)(x2+4x+1)2+4(x+4)(x2+4x+1)+4(x+4)2
(8)a2+2a+1+4b2﹣4ab﹣4b
参考答案
1.解:(1)(x﹣y)3﹣4(x﹣y)
=(x﹣y)[(x﹣y)2﹣4]
=(x﹣y)(x﹣y+2)(x﹣y﹣2);
(2)﹣2x3+12x2﹣18x
=﹣2x(x2﹣6x+9)
=﹣2x(x﹣3)2.
2.解:(1)m3﹣9m
=m(m2﹣9)
=m(m+3)(m﹣3);
(2)(x﹣y)2﹣(x+y)(x﹣y)
=(x﹣y)[(x﹣y)﹣(x+y)]
=﹣2y(x﹣y).
3.解:(1)(p﹣4)(p+1)+3p
=p2﹣3p﹣4+3p
=p2﹣4
=(p+2)(p﹣2);
(3)4xy2﹣4x2y﹣y3
=﹣y(4x2﹣4xy+y2)
=﹣y(2x﹣y)2.
4.解:(1)原式=4ab2(2a2+3bc);
(2)原式=a(a2﹣2a+1)=a(a﹣1)2;
(3)原式=(2x+y+x+2y)(2x+y﹣x﹣2y)=3(x+y)(x﹣y).
5.解:(1)ax+bx=x(a+b);
(2)x4﹣y4=(x2+y2)(x2﹣y2)
=(x2+y2)(x﹣y)(x+y);
(3)(a+b)2﹣4a(a+b)+4a2=(a+b﹣2a)2=(b﹣a)2.
6.解:(1)原式=2x(x2﹣4)=2x(x+2)(x﹣2);
(2)原式=x2+6xy+9y2﹣12xy,=x2﹣6xy+9y2,=(x﹣3y)2.
7.解:(1)(x﹣1)(x﹣3)+1
=x2﹣4x+3+1
=(x﹣2)2;
(2)a2(x﹣y)+4b2(y﹣x)
=(x﹣y)(a2﹣4b2)
=(x﹣y)(a+2b)(a﹣2b).
8.解:(1)原式=x3y﹣xy3,
=xy(x2﹣y2),
=xy(x+y)(x﹣y);
(2)原式=(x+2)(x+4)+(x+2)(x﹣2),
=(x+2)(x+4+x﹣2),
=(x+2)(2x+2),
=2(x+2)(x+1).
9.解:(1)原式=3x(x2﹣9)=3x(x+3)(x﹣3);
(2)原式=(y2+1﹣2y)(y2+1+2y)=(y﹣1)2(y+1)2.
10.解:(1)﹣2x2﹣8y2+8xy
(2)(p+q)2﹣(p﹣q)2
11.解:(1)原式=m3(x﹣2)﹣m(x﹣2),=m(x﹣2)(m2﹣1),
=m(x﹣2)(m+1)(m﹣1);
(2)原式=4ab﹣4a2﹣b2,=﹣(4a2﹣4ab+b2)=﹣(2a﹣b)2.
12.解:(1)原式=(x﹣1)2;
(2)原式=a2(1﹣m)﹣4(1﹣m)
=(1﹣m)(a2﹣4)
=(1﹣m)(a+2)(a﹣2);
(3)原式=(x﹣y)2﹣4(x﹣y)+4=(x﹣y﹣2)2.
13.解:(1)a3﹣a=a(a2﹣1)=a(a+1)(a﹣1);
(2)4ab2﹣4a2b﹣b3=﹣b(﹣4ab+4a2+b2)=﹣b(2a﹣b)2;
(3)a2(x﹣y)﹣9b2(x﹣y)
=(x﹣y)(a2﹣9b2)
=(x﹣y)(a+3b)(a﹣3b);
(4)(y2﹣1)2+6
(1﹣y2)+9
=(y2﹣1)2﹣6
(y2﹣1)+9=(y2﹣1﹣3)2=(y+2)2(y﹣2)2.
14.解:(1)原式=3a(x2﹣2xy+y2)=3a(x﹣y)2;
(2)原式=[3(a+b)+(a﹣b)][3(a+b)﹣(a﹣b)]
=(3a+3b+a﹣b)(3a+3b﹣a+b)
=(4a+2b)(2a+4b)=4(2a+b)(a+2b).
15.解:(1)原式=2(x2﹣25)
=2(x+5)(x﹣5);
(2)原式=(a﹣b)(a2﹣b2)
=(a﹣b)2(a+b).
16.解:(1)原式=4(a2﹣4)=4(a+2)(a﹣2);
(2)原式=(y﹣1﹣5)2=(y﹣6)2;
(3)原式=x2+6x+8+1=(x+3)2.
17.解:(1)3ab3﹣30a2b2+75a3b
=3ab(b2﹣10ab+25a2)=3ab(b﹣5a)2;
(2)a2(x﹣y)+16(y﹣x)=(x﹣y)(a2﹣16)=(x﹣y)(a+4)(a﹣4);
(3)(x2+y2)2﹣4x2y2=(x2+y2+2xy)(x2+y2﹣2xy)=(x+y)2(x﹣y)2.
18.解:(1)原式=ab(b﹣3a+1);
(2)原式=x(y2﹣1)=x(y+1)(y﹣1);
(3)原式=3(x2﹣2x+1)=3(x﹣1)2;
(4)原式=(4m2+9+12m)(4m2+9﹣12m)=(2m+3)2(2m﹣3)2.
19.解:(1)原式=(m+4)(m﹣4);
(2)原式=(2a﹣b)(x2﹣y2)=(2a﹣b)(x+y)(x﹣y);
(3)原式=(y﹣3)2;
(4)原式=(x2﹣4y2)2=(x+2y)2(x﹣2y)2.
20.解:(1)原式=(x+2y+y)(x+2y﹣y)=(x+3y)(x+y);
(2)原式=m2(m﹣1)﹣4(m﹣1)2
=(m﹣1)[m2﹣4(m﹣1)]
=(m﹣1)(m2﹣4m+4)
=(m﹣1)(m﹣2)2.
21.解:(1)原式=4(a2﹣4)
=4(a+2)(a﹣2);
(2)原式=[(y﹣1)﹣5]2
=(y﹣6)2.
22.解:(1)原式=2(a2﹣6ab+9b2)
=2(a﹣3b)2;
(2)原式=(x2﹣2y+1﹣2y)(x2﹣2y﹣1+2y)
=(x2﹣4y+1)(x+1)(x﹣1).
23.解:(1)原式=﹣4(a2x2﹣2ax+1)=﹣4(ax﹣1)2;
(2)原式=[3(2a+3b)+2(3a﹣2b)][3(2a+3b)﹣2(3a﹣2b)]=13b(2a+5b).
24.解:(1)3ax3﹣30ax2+75ax=3ax(x2﹣10x+25)=3ax(x﹣5)2
(2)(4m2+9)2﹣144m2
=(4m2+9+12m)(4m2+9﹣12m)=(2m+3)2(2m﹣3)2
(3)﹣5a2b﹣10a2b3+15a4b=﹣5a2b(1+2b2﹣3a2)
(4)5a3b(a﹣b)3﹣15a4b3(b﹣a)2
=5a3b(a﹣b)2(a﹣b﹣3ab2)
(5)3x2+2x+=(9x2+6x+1)=(3x+1)2
(6)(8a2+b2)2﹣(a2+8b2)2
=(8a2+b2+a2+8b2)(8a2+b2﹣a2﹣8b2)=9×7(a2+b2)(a2﹣b2)
=63(a2+b2)(a﹣b)(a+b);
(7)(x2+4x+1)2+4(x+4)(x2+4x+1)+4(x+4)2
=(x2+4x+1+2x+8)2=(x2+6x+9)2=(x+3)4
(8)a2+2a+1+4b2﹣4ab﹣4b=(a+1)2﹣4b(a+1)+4b2=(a+1﹣2b)2