1.已知集合A=｛a,a+b,a+b² ｝,B=｛a,ax,ax²｝,A=B,求x的值.2.已知集合A={x｜-2≤x≤5},B={x｜m+1≤x≤2m+1}.B含于A,求实数x的取值范围.3.已知A=｛2,3｝,M={2,5,a²-3a+5},N={1,3,a-6a+10},A含于M,且A含于N,求

1.已知集合A=｛a,a+b,a+b² ｝,B=｛a,ax,ax²｝,A=B,求x的值.2.已知集合A={x｜-2≤x≤5},B={x｜m+1≤x≤2m+1}.B含于A,求实数x的取值范围.3.已知A=｛2,3｝,M={2,5,a²-3a+5},N={1,3,a-6a+10},A含于M,且A含于N,求
1.已知集合A=｛a,a+b,a+b² ｝,B=｛a,ax,ax²｝,A=B,求x的值.
2.已知集合A={x｜-2≤x≤5},B={x｜m+1≤x≤2m+1}.B含于A,求实数x的取值范围.
3.已知A=｛2,3｝,M={2,5,a²-3a+5},N={1,3,a-6a+10},A含于M,且A含于N,求实数a的值.

1.已知集合A=｛a,a+b,a+b² ｝,B=｛a,ax,ax²｝,A=B,求x的值.2.已知集合A={x｜-2≤x≤5},B={x｜m+1≤x≤2m+1}.B含于A,求实数x的取值范围.3.已知A=｛2,3｝,M={2,5,a²-3a+5},N={1,3,a-6a+10},A含于M,且A含于N,求
1.已知集合A=｛a,a+b,a+b² ｝,B=｛a,ax,ax²｝,A=B,求x的值.
由a+b=ax,得 x=1+(b/a) .(1)
由a+b²=ax²,得x²=1+(b²/a).(2)
故有 [1+(b/a)]²=1+(b²/a),化简得 2b/a+(b²/a²)=b²/a,去分母得2ab+b²=ab²,∵b≠0,可消去b
得2a+b=ab,∴b=2a/(a-1),代入(1)式便得x=1+2/(a-1)=(a+1)/(a-1)
此时x²=(a+1)²/(a-1)²,于是ax=a(a+1)/(a-1),ax²=a(a+1)²/(a-1)²,
a+b=a+2a/(a-1)=(a²-a+2a)/(a-1)=a(a+1)/(a-1)=ax
a+b²=a+4a²/(a-1)²=[a(a-1)²+4a²]/(a-1)²=a(a+1)²/(a-1)²=ax²
故有A=B
2.已知集合A={x｜-2≤x≤5},B={x｜m+1≤x≤2m+1}.B⊆A,求实数x的取值范围.
m+1≧-2,得m≧-3；2m+1≦5,得m≦2；故-3≦m≦2.
3.已知A=｛2,3｝,M={2,5,a²-3a+5},N={1,3,a²-6a+10},A⊂M,且A⊂N,求实数a的值.
由a²-3a+5=3,得a²-3a+2=(a-2)(a-1)=0,故a=1或2.(1)；
由a²-6a+10=2,得a²-6a+8=(a-2)(a-40=0,故a=2或4.(2)；
(1)∩(2)={a︱a=2}
此时,M={2,5,3}；N={1,3,2}.

哈哈。不好意思，我不怎么会第一个问题应该是：X等于（a+b*b)/(a+b)或者/(a+b)/(a+b*b).当然还要考虑分母是不是零的情况！