What is the zero of this polynomial HELP!

You make and sell triangular flags. each flag has a base of  3.53.5  feet and a height of  2.52.5  feet. fabric for the flags costs  $0.40$0.40  per square foot. what is the cost to make one flag?

Fiona joins a fruit of the month club. the entry cost was $25 and then she pays $18 per month. if she participates for 8 months, how much will she pay in all? how much in 10 months?

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.