4(2)单项式与多项式相乘一、选择题1.化简2(21)(2)xxxx的结果是()A.3xxB.3xxC.21xD.31x2.化简()()()abcbcacab的结果是()A.222abbcacB.22abbcC.2abD.2bc3.如图14-2是L形钢条截面,它的面积为()A.ac+bcB.ac+(b-c)cC.(a-c)c+(b-c)cD.a+b+2c+(a-c)+(b-c)4.下列各式中计算错误的是()A.3422(231)462xxxxxxB.232(1)bbbbbbC.231(22)2xxxxD.342232(31)2323xxxxxx5.2211(6)(6)23abababab的结果为()A.2236abB.3222536ababC.2332223236abababD.232236abab二、填空题1.22(3)(21)xxx
2.321(248)()2xxx
3.222(1)3(1)abababab
4.2232(3)(23)3(25)xxxxxx
5.228(34)(3)mmmmm
6.7(21)3(41)2(3)1xxxxxx
7.22223(2)()abababa
8.223263()(2)2(1)xxyxxy
9.当t=1时,代数式322[23(22)]ttttt的值为
10.若20xy,则代数式3342()xxyxyy的值为
三、解答题1.计算下列各题(1)111()()(2)326aababab(2)32222211(2)(2)()342xyxyxyxyxyz(3)223121(3)()232xyyxy(