设集合A={2,-1,x²-x+1},B={2y,-4,x+4},C={-1,7} 且A∩B=C 求实数x,y的值及A∪B集合A={x|x²-3x+2=0},B={x|2x²-ax+2=0} 若A∪B=A 求实数a的值
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![设集合A={2,-1,x²-x+1},B={2y,-4,x+4},C={-1,7} 且A∩B=C 求实数x,y的值及A∪B集合A={x|x²-3x+2=0},B={x|2x²-ax+2=0} 若A∪B=A 求实数a的值](/uploads/image/z/1984635-27-5.jpg?t=%E8%AE%BE%E9%9B%86%E5%90%88A%3D%7B2%2C-1%2Cx%26%23178%3B-x%2B1%7D%2CB%3D%7B2y%2C-4%2Cx%2B4%7D%2CC%3D%7B-1%2C7%7D+%E4%B8%94A%E2%88%A9B%3DC+%E6%B1%82%E5%AE%9E%E6%95%B0x%2Cy%E7%9A%84%E5%80%BC%E5%8F%8AA%E2%88%AAB%E9%9B%86%E5%90%88A%3D%7Bx%7Cx%26%23178%3B-3x%2B2%3D0%7D%2CB%3D%7Bx%7C2x%26%23178%3B-ax%2B2%3D0%7D+%E8%8B%A5A%E2%88%AAB%3DA+%E6%B1%82%E5%AE%9E%E6%95%B0a%E7%9A%84%E5%80%BC)
设集合A={2,-1,x²-x+1},B={2y,-4,x+4},C={-1,7} 且A∩B=C 求实数x,y的值及A∪B集合A={x|x²-3x+2=0},B={x|2x²-ax+2=0} 若A∪B=A 求实数a的值
设集合A={2,-1,x²-x+1},B={2y,-4,x+4},C={-1,7} 且A∩B=C 求实数x,y的值及A∪B
集合A={x|x²-3x+2=0},B={x|2x²-ax+2=0} 若A∪B=A 求实数a的值
设集合A={2,-1,x²-x+1},B={2y,-4,x+4},C={-1,7} 且A∩B=C 求实数x,y的值及A∪B集合A={x|x²-3x+2=0},B={x|2x²-ax+2=0} 若A∪B=A 求实数a的值
设集合A={2,-1,x²-x+1},B={2y,-4,x+4},C={-1,7} 且A∩B=C 求实数x,y的值及A∪B
A∩B=C得7属于B,则有两种情况
(1)2y=7且x+4=-1,即y=7/2或x=-5.经检验不符合题意.
(2)2y=-1且x+4=7,即y=-1/2或x=3.经检验符合题意.
所以y=-1/2或x=3,此时A={2,-1,7},B={-1,-4,7},A∪B={-1,-4,2,7}
集合A={x|x²-3x+2=0},B={x|2x²-ax+2=0} 若A∪B=A 求实数a的值
A={1,2},A∪B=A即B是A的子集,有以下情况
(1)B是空集,即2x²-ax+2=0无实根,所以(-a)²-16