What is the mean of 90, 55, 75, 60, 80, and 90?

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Inez has a phone card. the graph shows the number of minutes that remain on her phone card a certain number of days.

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x