F(x) = 5x2 - X+ 3

Please help

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

There were 25 students who answered to a survey about sports. four-fifths of them like football. how many students like football?

The given diagram shows the parts of a right triangle with an altitude to the hypotenuse. using the two given  measures, find the other four.