Question 943243
graph of {{{y=(-5/2)x-1/2}}}
{{{ graph( 500, 500, -10, 10, -10, 10, (-5/2)x-1/2 ) }}} 
graph of {{{y=-5/(2x)-1/2}}}
{{{ graph( 500, 500, -10, 10, -10, 10, -5/2x-1/2 ) }}} 
Perhaps one of these is what you're looking for.  The equation is somewhat ambiguous.