Question 705865
slope of desired line is -1/9 because product of slopes for perpendicular lines is -1.


{{{y=-(1/9)x+b}}}, and we will want to find b.
{{{b=y+(1/9)x}}}
Our point which must be on this line is x=5, y=4.


b=(4)+(1/9)(5)
b=4+5/9
b=(36+5)/9
b=41/9
Desired equation for our line is {{{y=-(1/9)x+41/9}}}.  Notice all constant values are kept in rational form, no decimals, to ensure ease in converting equation to use only whole or interger numbers.  


That's still in general form and otherwise unfinished; Now maybe you can finish.