Question 934267
The perpendicular line n is something like 2x+2y=c and this line n is given to contain (2,5).  Use this point to find c.


{{{2*2+2*5=c}}}
{{{4+10=c}}}
{{{c=14}}}


Line n is {{{2x+2y=14}}}, simplifying to {{{highlight(x+y=7)}}}.