1、初中、高中衔接课第1课时因式分解一、选择题1.计算(2)100(2)101的结果是()A.2 B.2 C.2100 D.2100答案C解析(2)100(2)101 (2)100(2)(2)100 (2)100 (12)(2)100 2100 ,故选C.2.边长为a,b的长方形周长为12,面积为10,则a2bab2的值为()A.120 B.60 C.80 D.40答案B解析边长为a,b的长方形周长为12,面积为10,ab6,ab10,则a2bab2ab(ab)10660.故选B.3.下列各式中,能运用两数和(差)的平方公式进行因式分解的是()A.x24x B.a24b2C.x24x1 D.x22
2、x1答案D解析x24xx(x4),故A项错误;a24b2(a2b)(a2b),故B项错误;x24x1不能分解,故C项错误;x22x1(x1)2,故D项正确.故选D.4.将代数式x24x5因式分解的结果为()A.(x5)(x1) B.(x5)(x1)C.(x5)(x1) D.(x5)(x1)答案A解析x24x5(x5)(x1),故选A.5.要在二次三项式x2()x6的括号中填上一个整数,使它能按公式x2(ab)xab(xa)(xb)分解因式,那么这些数只能是()A.1,1 B.5,5C.1,1,5,5 D.以上答案都不对答案C解析6可以分成:23,2(3),16,1(6),括号中填上的整数应该是
3、6的两个因数的和,即1,1,5,5.故选C.6.已知多项式x2bxc因式分解的结果为(x1)(x2),则bc的值为()A.3 B.2 C.1 D.0答案C解析(x1)(x2)x22xx2x2x2,b1,c2,bc1.故选C.7.下列变形正确的是()A.x3x2xx(x2x)B.x23x2x(x3)2C.a29(a3)(a3)D.a24a4(a2)2答案C解析x3x2xx(x2x1),故A项错误;x23x2(x1)(x2),故B项错误;a29(a3)(a3),故C项正确;a24a4(a2)2,故D项错误.故选C.8.若2mn25,m2n2,则(m3n)2(3mn)2的值为()A.200 B.20
4、0 C.100 D.100答案B解析2mn25,m2n2,(m3n)2(3mn)2(m3n)(3mn)(m3n)(3mn)(4m2n)(2m4n)4(2mn)(m2n)4252200.故选B.二、填空题9.因式分解:axaybxby_.答案(ab)(xy)解析axaybxby,(axay)(bxby),a(xy)b(xy),(ab)(xy).10.因式分解:(xy)22y(xy)_.答案(xy)(xy)解析原式(xy)(xy2y)(xy)(xy).11.分解因式:(a21)24a2_.答案(a1)2(a1)2解析(a21)24a2(a212a)(a212a)(a1)2(a1)2.三、解答题12
5、.分解因式:(1)x26x8;(2)x2x6.解(1)x26x8(x2)(x4).(2)x2x6(x2)(x3).13.分解因式:x22xy8y2.解x22xy8y2(x4y)(x2y).14.若x(x1)y(xyy)(x1)M,则M_.答案xy2解析x(x1)y(xyy)(x1)M,x(x1)y2(x1)(x1)M0,(x1)(xy2M)0,x1,xy2M0,即Mxy2.15.分解因式:(1)(xy)24(xy)3;(2)m(m2)(m22m2)3.解(1)令Axy,则原式A24A3(A1)(A3),所以(xy)24(xy)3(xy1)(xy3).(2)令Bm22m,则原式B(B2)3B22B3(B1)(B3),所以原式(m22m1)(m22m3)(m1)2(m1)(m3).