Question 33534
{{{ -2x - 5y <= 10 }}}
{{{ 2x + 5y >= -10 }}}
{{{ 5y >= -2x -10 }}}
{{{ y >= -(2/5)x - 2 }}}


So, we need to draw the line {{{ y = -(2/5)x - 2 }}} which goes through (0,-2).


Need to find one more point. Lets pick when x=5...
{{{ y = -(2/5)(5) - 2 }}}
{{{ y = -2 - 2 }}}
y=-4


So we have {{{graph(300,300, -10,2,-4,4,-(2/5)x - 2) }}}


Now we need to know the region {{{ y >= -(2/5)x - 2 }}}. Hopefully, from common sense, if you are OK with graphs, you can tell if this is the region above or below the line.


If you cannot decide, then pick any point off line, the obvious one being the origin (0,0) which is above the line:
y and {{{ -(2/5)x - 2 }}}
0 and {{{ -(2/5)(0) - 2 }}}
0 and -2
0 is greater than -2


So (0,0) lies in the region where y is greater than {{{ -(2/5)x - 2 }}}


So, the region {{{ y >= -(2/5)x - 2 }}} is that one ABOVE the line.


jon.