X + y=5
2x - y=1

What is the determinant of the coefficient matrix?

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Mrs. blake's bill at a restaurant is $42.75. she wants to leave the waiter an 18% tip. how much will she pay in all, including the tip?

The room above is shaped like a rectangle and has a perimeter of 34 feet. if the room is 11 feet long, how wide is it?