Which of following expressions is a polynomial? f(x)=1/5x^2+4.5x+2, f(x)=-3x^4+8x^2-2sqrtx+1, f(x)=-2.1x^7+3x^2+17/2x, f(x)=4/x-11x^2

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.

Captain umaima has a ship, the h.m.s. khan. the ship is two furlongs from the dread pirate nadia and her merciless band of thieves. the captain has probability 3/7 of hitting the pirate ship. the pirate only has one good eye, so she hits the captain's ship with probability 2/5. if both fire their cannons at the same time, what is the probability that the captain hits the pirate ship, but the pirate misses.