6.8.35 Set Theory

Condition: establish a correspondence between the specified numbers and the sets that they belong. \ [\ begin {array} {l} x_ {1} = 0.5, \ quad x_ {2} =-\ sqrt {5}, \ quad X_ {3} = 2 \\ A = \ \ in {z} \ Mid- \ SQRT {5} \ leQ x <3 \} \\ b = \ \ \ in \ in {n} \ mica-3