问题描述: 设集合A={x2,2x-1,-4},B={x-5,1-x,9},若A∩B={9},求x的值及A∪B. 1个回答 分类:数学 2014-11-18 问题解答: 我来补答 ∵集合A={x2,2x-1,-4},B={x-5,1-x,9},且A∩B={9},∴x2=9或2x-1=9,解得:x=3或-3或5,当x=3时,A={-4,9,5},B={9,-2},不合题意;当x=-3时,A={-4,9,-7},B={9,4,-8},符合题意;当x=5时,A={-4,9,25},B={9,0,-4},不合题意,∴x的值为-3,即A={-4,9,-7},B={9,4,-8},则A∪B={-4,-8,-7,4,9}. 展开全文阅读