If the two right lines is parallel than theirs coefficient of direction is equal.
The explicit form of the right line is y=kx+l , where k is coefficient of direction and l is intersection with y axis.
In our case k=12 and when we replace (x,y) = (10,-5) in equation we get
-5=12 * 10 + l => l=-125 and equation is y=12x-125
Good luck!!!