2v squared +4v-2 solved by completing the square

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin. how many doctors use brand x aspirin

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?

The perimeter of a quarter circle is 14.28 miles. what is the quarter circle's radius?