Each week, Darin's Lawn Service mows 90 lawns in 45 hours at a housing complex. The lawns in the complex are the same size. At this rate, how many hours will it take Darin to mow 12 lawns?

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

An equation representing lyle’s hedge-trimming business is a = 12n - 300 where a is the amount of profit or loss in dollars and n is the number of hedges trimmed. how would the graph of lyle’s business change if the equation a = 10n - 300 represented his business? the graph would be flatter. the graph would be steeper. the graph would start closer to the origin. the graph would start lower on the y-axis.

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.