题目
如果关于x的多项式5x2﹣(2yn+1﹣mx2)﹣3(x2+1)的值与x的取值无关,且该多项式的次数是三次.求m,n的值. 答案:解:5x2﹣(2yn+1﹣mx2)﹣3(x2+1)=5x2﹣2yn+1+mx2﹣3x2﹣3=(5+m﹣3)x2﹣2yn+1﹣3=(2+m)x2﹣2yn+1﹣3由题意得,2+m=0,n+1=3,解得,m=﹣2,n=2设集合A={x|x=3n+1,nÎ
Z},B={x|x=3n-2,nÎ
Z},C={x|x=6n+1,nÎ
Z},那么
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A.A=BC
B.CBA
C.CAB
D.AB=C