求解答4567题
1个回答

4.(x-1)(x-a)≥0 6.(x-1)²当a≥1时,x≤1或x≥a => x²-5x+8-x≤log2(1)

=>-x≤0

=> x≥0

x²-6x+8≤0

(x-2)(x-4)≤0

=> 2≤x≤4

C R(B)=x4

A∩C R(B)=0≤x4