<PRE><B>Question 1187715</B>

1. 
{{{x+y &gt; 3}}}
{{{x-y&lt; 3 }}}

({{{2}}},{{{6}}})

{{{2+6 &gt; 3}}}=&gt;{{{8&gt;3}}}-&gt; true
{{{2-6&lt; 3 }}}=&gt;{{{-4&lt;3}}}-&gt; true

=&gt;({{{2}}},{{{6}}}) IS  solution of the system


2. 

{{{2x-15y&gt;8}}}
{{{x-3 &lt; -2}}}

 ( {{{10}}},{{{-2}}})

{{{2*10-15(-2) &gt;8}}}=&gt;{{{20+30 &gt;8}}}=&gt;{{{50 &gt;8}}}-&gt; true
{{{10-3 &lt; -2}}}=&gt; {{{7&lt;-2}}}-&gt; false

=&gt;  ( {{{10}}},{{{-2}}}) is {{{not}}} solution of the system


3. 

{{{x+y &gt; 4}}}
{{{y-x&gt; 2}}}
 
({{{3}}},{{{8}}})

{{{3+8 &gt; 4}}}=&gt; {{{11&gt;4}}}-&gt; true
{{{8-3&gt; 2}}} =&gt;{{{5&gt;2}}}-&gt; true

=&gt; ({{{3}}},{{{8}}})  IS  solution of the system

4. 
5x &gt;y
2y ???????????????

5. 

{{{3x+y&gt;7}}}
{{{2x-5y&lt;-1}}}

 ({{{-5}}},{{{7}}})

{{{3(-5)+7&gt;7 }}}=&gt;{{{-15+7&gt;7}}} =&gt;{{{-8&gt;7}}}-&gt; false
{{{2(-5)-5*7&lt;-1}}}=&gt;{{{-10-35&lt;-1}}} =&gt; {{{-45&lt;-1}}}-&gt; true

=? ({{{-5}}},{{{7}}}) is {{{not}}} solution of the system

</PRE>