1+5a-9(-2+5a) how do i solve this? i have know idea how this works.

Suppose sat writing scores are normally distributed with a mean of 497 and a standard deviation of 109. a university plans to award scholarships to students whose scores are in the top 2%. what is the minimum score required for the scholarship? round your answer to the nearest whole number, if necessary.

How do you write something in scientific notation?

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day