What is 61,090,000 expressed in scientific notation

Awrestling tournament begins with 128 competitors. in the first round, each competitor has 1 match against another wrestler. the winner of each match moves on to the next round until there is a winner. write a sequence in which the terms represent the number of players still in the tournament at the end of each round. describe the sequence? how many rounds are in the tournament?

You drop a rubber ball off the roof of a 50 meter high building onto a paved parking lot. it bounces back up with every bounce, but not quite all the way back up to you. after the first bounce it bounces back only 80 percent of the distance it was dropped from. the pattern continues, meaning after every bounce it comes up to just 80 percent of the previous maximum height. so if before the first bounce the height is 50 meters, what height does the ball reach after the fifth bounce? round your answer to one decimal place and chose the correct response from the choices below:

When x = 3 and y = 5, by how much does the value of 3x2 – 2y exceed the value of 2x2 – 3y ?