To work out who the unknowns in the room are, we can establish that c = p+ 9
c + p = 25. The unknowns in the room are there the total number of
parents in the room, and the total number of teachers in the room.
Solutions just means the amount of times the lines intersect, so there are no solutions. Since the lines are parallel, they’re going the exact same direction forever and ever, never intersecting. Hope this helps!