Question 723942
1. numbers {{{less}}} than {{{zero}}}: 
{.{{{-1}}},{{{-2}}},{{{-4}}},{{{-6}}},{{{-8}}},.....{{{-infinity}}}.}

 but greater than {.{{{1}}}: {{{2}}},{{{3}}},{{{4}}},{{{5}}},.....{{{infinity}}}.} 

as you can see, there are no common elements; so,

{{{True}}}, is the {{{empty}}} set 



2. {{{False}}}, it is {{{infinite}}}

{ {{{-2}}},{{{-4}}},{{{-6}}},{{{-8}}},.....{{{-infinity}}}}


3. If the replacement set of {{{x}}} is {1, 2, 3, 4, 5}, then the solution set for the statement is {{{3x=27}}} is {9}.

{{{False}}}, there is no {{{9}}} in the replacement set of {{{x}}}