Step-by-step explanation:
let p (-5,12)=(x1,y1) & Q (x,y)=(x2,y2)
now,
midpoint =(x1+x2)/2 , (y1+y2)/2
(5,3)=(-5+x2)/2 , (12+y2)/2
equating them,we get,
5=(-5+x2)/2 , 3=(12+y2)/2
5×2=-5+x2 , 3×2=12+y2
10+5=x2 , 6=12+y2
x2=15 , 6-12=y2
y2=-6
so, Q(x,y)=Q (15,-6)
