Question

用列举法表示集合{x∈R|（x-1）^2（x+1）=0} {x∈N|6/（6-x）∈N {2,4,6,8} {1,1/2

Answer 1

{x∈R|（x-1）^2（x+1）=0} = { -1,1}

{x∈N|6/（6-x）∈N } = {3,4,5 }

{2,4,6,8}

{1,1/2,1/3,1/4}