Question 874691
{{{3x+5y=15}}}
{{{5y=-3x+15}}}
{{{y=-(3/5)x+15}}}, your given equation in slope-intercept form.


The negative reciprocal of that slope is {{{5/3}}}, and this then is the slope for a line perpendicular to {{{y=-(3/5)x+15}}}.


Using a more general equation for what you search for, {{{y=(5/3)x+b}}}, and you will use the point to be on this line to determine b.  This is left for you to finish.