數(shù)學(xué)七年級(jí)下北師大版1.6整式的乘法同步練習(xí)1

1、PAGE 1.6 整式的乘法(總分100分 時(shí)間40分鐘)一、填空題:(每題3分,共27分)1.(-3xy)(-x2z)6xy2z=_.2. 2(a+b)25(a+b)33(a+b)5=_.3.(2x2-3xy+4y2)(-xy)=_.4.3a(a2-2a+1)-2a2(a-3)=_.5.已知有理數(shù)a、b、c滿足a-1+a+b+a+b+c-2=0,則代數(shù)式(-3ab).(-a2c).6ab2的值為_6.(a+2)(a-2)(a2+4)=_.7.已知(3x+1)(x-1)-(x+3)(5x-6)=x2-10 x+m,則m=_.8.已知ax2+bx+1與2x2-3x+1的積不含x3的項(xiàng),也不含x的

2、項(xiàng),那么a=_,b=_.9.=_.二、選擇題:(每題4分,共32分)10.若,則M、a的值可為( ) A.M=8,a=8 B.M=2,a=9 C.M=8,a=10 D.M=5,a=1011.三個(gè)連續(xù)奇數(shù),若中間一個(gè)為n,則它們的積為( ) A.6n2-6n B.4n3-n C.n3-4n D.n3-n12.下列計(jì)算中正確的個(gè)數(shù)為( ) (2a-b)(4a2+4ab+b2)=8a3-b3 (-a-b)2=a2-2ab+b2 (a+b)(b-a)=a2-b2 (2a+b)2=4a2+2ab+b2 A.1 B.2 C.3 D.413.設(shè)多項(xiàng)式A是個(gè)三項(xiàng)式,B是個(gè)四項(xiàng)式,則AB的結(jié)果的多項(xiàng)式的項(xiàng)數(shù)一定

3、是( ) A.多于7項(xiàng) B.不多于7項(xiàng) C.多于12項(xiàng) D.不多于12項(xiàng)14.當(dāng)n為偶數(shù)時(shí),與的關(guān)系是( ) A.相等 B.互為相反數(shù) C.當(dāng)m為偶數(shù)時(shí)互為相反數(shù),當(dāng)m為奇數(shù)時(shí)相等 D.當(dāng)m為偶數(shù)時(shí)相等,當(dāng)m為奇數(shù)時(shí)為互為相反數(shù)15.若,則下列等式正確的是( ) A.abcde0 B.abcde0 D.bd016.已知aN B.M=N C.MN D.無法確定三、解答題:(共41分)18.(1)解方程4(x-2)(x+5)-(2x-3)(2x+1)=5.(3分) (2)化簡求值:x(x2-4)-(x+3)(x2-3x+2)-2x(x-2),其中x=1.5.(3分)19.已知,且m是n的2倍,求m

4、、n(5分)20.已知x+3y=0,求的值.(6分)21.在多項(xiàng)式中,當(dāng)x=3時(shí),多項(xiàng)式的值為5,求當(dāng)x=-3時(shí),多項(xiàng)式的值.(6分)22.求證:多項(xiàng)式(a-2)(a2+2a+4)-3a(a+1)2-2a(a-1)2-(3a+1)(3a-1)+a(1+a)的值與a的取值無關(guān).23.求證:N= 能被13整除.(6分)24.求N=是幾位正整數(shù).(6分)答案:1.18x4y3z2 2.30(a+b)10 3.-2x3y+3x2y2-4xy3 4.a3+3a 5.-36 6.a4-16 7.-3x3-x+17 8.2,3 9. 10.C 11.C 12.C 13.D 14.D 15.D 16.B 17.A 18.(1)x= (2)019. 20.x+3y=0 x3+3x2y-2x-6y=x2(x+3y)-2(x+3y)=x20-20=021.由題意得35a+33b+ 35a+33b+ (-3)5a+(-3)3b+