Neither orthogonal nor parallel
1) Let's have a view for those vectors
Two vectors are parallel if they share the same direction, so they are not parallel ones
Two vectors are orthogonal ones if they form a 90º angle between themselves and their scalar product is zero
so u <-24,18> and v =<6,-7> u * v =
-24*(6) +18(-7)=-144-126≠0
2) So based on that, they are neither orthogonal nor parallel.