What is the value of the expression x^2y–y+xy^2–x for x=4 and y=0.25?

The head librarian at the library of congress has asked her assistant for an interval estimate of the mean number of books checked out each day. the assistant provides the following interval estimate: from 740 to 920 books per day. what is an efficient, unbiased point estimate of the number of books checked out each day at the library of congress?

Aiden buys two bags of chips at $1.09 each and a 20 ounce soda for $1.20 at the gas station. he knows that the state tax is 5.5. how much change will he receive from a $5 bill?

The lengths of all sides of a triangle are integers when measured in decimeters. one of the sides has length of 1 dm and another of 3 dm. find the perimeter of the triangle.'