已知集合A={x丨x^2-3x-10

题目

已知集合A={x丨x^2-3x-10<=0},B={x丨m+1<=x<=2m-1},且B ⊆A,求实数m的取值范围

答案

x^2-3x-10<=0
(x-5)(x+2)<=0
-2<=x<=5
由B包含于A则-2<=m+1<=5 ,-2<=2m-1<=5 ,m+1<=2m-1
解得1<=m<=3