Find the x-coordinate of the vertex of the function given below. You may enter just the number
y = x2 + 14x+21

Solve this problem! extra ! 3025/5.5 = a/90.75

Yo need asap pls ! markin da brainiest too !

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?