TheshortestwaytodomanythingsistoonlyonethingatatimeandAllthingsintheirbeingaregoodforsomethingandSufferingisthemostpowerfulteacheroflife1整式的乘法知识点及相关习题复习1.同底数幂的乘法同底数幂相乘,底数不变,指数相加,用字母表示为a.a=a(m、n都是正整数)mnnm练习:(1)(2)32aaa32)(xx(3)(4)32333312nnxx(5)(6)mm2224aaann23122.幂的乘方幂的乘方,底数不变,指数相乘。用字母表示为(a)m=a(m、n都是正整数)nmn3.积的乘方积的乘方,等于把积的每一个因式分别乘方,再把所得的幂相乘。用字母表示为(ab)=a.b(n为正整数)nnn练习:-(2x2y4)3(-a)3·(an)5·(a1-n)5[(102)3]4[(a+b)2]4[-(-x)5]2(xa·xb)c4.整式的乘法1)单项式的乘法单项式与单项式相乘,把它们的系数、相同字母分别相乘,对于只TheshortestwaytodomanythingsistoonlyonethingatatimeandAllthingsintheirbeingaregoodforsomethingandSufferingisthemostpowerfulteacheroflife2在一个单项式里含的字母,则连同它的指数作为积的一个因式。练习:)3()21(23322yxzyxxy)()()3(343yxyx)104)(105.2)(102.1(911311215nnnyxyx2)单项式与多项式相乘单项式与多项式相乘,就是用单项式去乘多项式的每一项,再把所得的积相加。练习:22(3)(21)xxx321(248)()2xxx223121(3)()232xyyxy3212[2()]43abaabb3)多项式与多项式相乘多项式与多项式相乘,先用一个多项式的每一项乘另一个多项式的每一项,再把所得的积相加。练习:(3x-1)(4x+5)(-4x-y)(-5x+2y)(y-1)(y-2)(y-3)(3x2+2x+1)(2x2+3x-1)2.乘法公式TheshortestwaytodomanythingsistoonlyonethingatatimeandAllthingsintheirbeingaregoodforsomethingandSufferingisthemostpowerfulteacheroflife31)平方差公式两个数的和与这两个数的差的积,等于这两个数的平方差。用字母表示为(a+b)(a-b)=a-b22(-2+ab)(2+ab)(-2x+3y)(-2x-3y)(12m-3)(12m+3)(2x+y+z)(2x-y-z)2)完全平方公式两数和(或差)的平方,等于它们的平方和,加上(或减去)它们的积的2倍。用字母表示为(a+b)=a+2ab+b(a-b)=a-222222ab+b2(-2x+5)2(13x+6y)2(a+2b-1)2(34x-23y)2经典习题1.nnyxyx212)()(2._____________)3)(3()2)(1(xxxx3.______________)x1)(x1)(x1)(x1(424.已知________x,60,1722yxyyx5.如果三角形的底边为(3a+2b),高为(9a2-6ab+4b2),则面积=__________.TheshortestwaytodomanythingsistoonlyonethingatatimeandAllthingsintheirbeingaregoodforsomethingandSufferingisthemostpowerfulteacheroflife46.-(x-y)2·(y-x)3=_____.7.如果多项式是一个完全平方式,则k的值是kxx82。8.可以写成()333mxA、B、C、D、13mx33xxm13mxx33xxm9.,则=()3,2nmaamnaA、5B、6C、8D、910.计算(-2)100+(-2)99所得的结果是()A.-2B.2C.299D.-29911.已知:有理数满足,则的值为(0|4|)4(22nnm22nm)A.±1B.1C.±2D.212.计算(2+1)(22+1)(24+1)(28+1)得()(A)48-1;(B)264-1;(C)26-1;(D)23-113.化简的结果是( )()()()abcbcacabA.B.222abbcac22abbcC.D.2ab2bc14.(x+1)(x-1)与(x4+x2+1)的积是()A.x6+1B.x6+2x3+1C.x6-1D.x6-2x3+115.计算结果是()2233)108.0()105.2(A.B.C.D.131061310613102141016.计算)47(123)5(232yxyxxyTheshortestwaytodomanythingsistoonlyonethingatatimeandAllthingsintheirbeingaregoodforsomethingandSufferingisthemostpowerfulteacheroflife5)3)(3()2)(1(xxxx(3x+2y)(2x+3y)-(x-3y)(3x+4y)