Question 484889
{{{y=(4/9)x-12}}}..as you can see, this line has a {{{slope}}} {{{m=4/9}}}

by definition, perpendicular lines have opposite reciprocal slopes

so, a {{{slope}}} of a line that is perpendicular to the given line will be: 

{{{m1=-9/4}}}


{{{y=(4/9)x-12}}}

{{{y=-(9/4)x}}}.......this is a line that is perpendicular to the given line

{{{ graph( 500, 500, -10, 10, -15, 10, (4/9)x-12,-(9/4)x) }}}