作业帮已知集合｛x│x+（a-1）x+b=0｝=｛a｝,求a,b的值.
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已知集合｛x│x+（a-1）x+b=0｝=｛a｝,求a,b的值.
已知集合｛x│x+（a-1）x+b=0｝=｛a｝,求a,b的值.
已知集合｛x│x+（a-1）x+b=0｝=｛a｝,求a,b的值.
A={x|x+(a-1)x+b=0}仅有一元素a,△=0,根据求根公式得x=-（a-1）/2=a 解a=1/3.将a带入方程则b=1/9 有疑问欢迎追问,多谢了~
x+（a-1）x+b=0 ==> a^2 + (a-1) * a + b =0 ==> a^2 + a^2 -a + b = 0 ==> 2a^2 - a + b = 0 (1) x+（a-1）x+b= {a} ==> delt = (a -1)^2 - 4b = 0 ==> (a-1)^2 = 4b (2) (1) * 4 + (2) ==> 8a^2 - 4a + 4b + (a-1)^2...
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x+（a-1）x+b=0 ==> a^2 + (a-1) * a + b =0 ==> a^2 + a^2 -a + b = 0 ==> 2a^2 - a + b = 0 (1) x+（a-1）x+b= {a} ==> delt = (a -1)^2 - 4b = 0 ==> (a-1)^2 = 4b (2) (1) * 4 + (2) ==> 8a^2 - 4a + 4b + (a-1)^2 = 4b ==> 8a^2 - 4a + 4b + a^2 - 2a + 1 = 4b ==> 9a^2 - 6a + 1 = 0 ==> (3a - 1)^2 =0 ==> a =1/3 2a^2 - a + b = 0 ==> b = a -2a^2 ==> b = 1/3 - 2 * (1/3)^2 ==> b =1/3 - 2/9 ==> b = 1/9 a = 1/3, b =1/9
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