Sistemas de desigualdades lineales ubicado en el plano, porfavorrr. ayudaa​

How many different ways can you make change for $.50 using only nickels, dimes, and quarters?

Alake near the arctic circle is covered by a 222-meter-thick sheet of ice during the cold winter months. when spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate. after 333 weeks, the sheet is only 1.251.251, point, 25 meters thick. let s(t)s(t)s, left parenthesis, t, right parenthesis denote the ice sheet's thickness sss (measured in meters) as a function of time ttt (measured in weeks).

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.