八年级上册数学期末必考因式分解特训50道(空白版+答案)

八年级上册数学期末必考因式分解特训50道(空白版+答案)

  • 简介

    1.因式分解: (1)8ab+2a; (2)x2y+2xy﹣15y; (3)9(x+2y)2﹣4(x﹣y)2; (4)a2+4ab﹣1+4b2. 解:(1)8ab+2a=2a(4b+1). (2)x2y+2xy﹣15y=y(x2+2x﹣15)=y(x+5)(x﹣3). (3)9(x+2y)2﹣4(x﹣y)2 =[3(x+2y)+2(x﹣y)][3(x+2y)﹣2(x﹣y)] =(3x+6y+2x﹣2y)(3x+6y﹣2x+2y) =(5x+4y)(x+8y). (4)a2+4ab﹣1+4b2. =(a2+4ab+4b2)﹣1 =(a+2b)2﹣1 =(a+2b+1)(a+2b﹣1). 2.将下列多项式因式分解 (1)8x2﹣4xy (2)3x4+6x3y+3x2y2 (3)a2﹣ab+ac﹣bc 解:(1)原式=4x(2x﹣y); (2)原式=3x2(x2+2xy+y2) =3x2(x+y)2; (3)原式=a(a﹣b)+c(a﹣b) =(a﹣b)(a+c).

八年级上册数学期末必考因式分解特训50道(空白版+答案)