If anybody is good at equivalent polynomial expressions

Iwill make brain if you me correctly fill this out needs due today pls and send it back to me (click the link and you will get it)

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:

You are at a restaurant and owe $56.20 for your meal. you want to leave an 18% tip. approximately how much is your tip?