X + 5 + (-1) = -5x - 1

Your friend swims on the school team. in his first four races, his times are 24.7, 23.5, 25.6, and 27.2 seconds. which time listed for his next race would make the range larger?

Which of the following expressions are equivalent ?

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36