Question

已知集合A=｛x|x^2-3x+2=0},B={x|x^2-ax+a-1=0},C=｛x|x-x+2m=0}.若AUB=

Answer 1

A=｛x|x^2-3x+2=0}

= {x|(x-1)(x-2)=0

= {1,2}

AUB=A => B is subset of A

when x=1,B={x|x^2-ax+a-1=0},

1-a+a-1=0 => 0=0

when x=2

4-2a+a-1=0

a=3 #

A∩C=C => C is subset of A

when x=1,C=｛x|x^2-x+2m=0}

1-1+2m =0

m =0

when x=2

4-2+2m =0

m = -1

m = 0 or -1#