Simplfy... PLZ HEL 3x^2 - 4x + 8 + 5x^2 + 9x - 10

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

The table shows the webster family’s monthly expenses for the first three months of the year. they are $2,687.44, $2,613.09, and $2,808.64. what is the average monthly expenditure for all expenses?

Explain how you can use the associative property to evaluate (7x50)x4.