8 percent =.08 as a decimal. to get the decimal of a percent pretend 8 percent is an 8 with an invisible decimal point at its right. so 8% is 8.0. to get a decimal of a percent, move the point two times to the left, and you will put in a 0 for the blank. so its ._8, where he blank is 0 and so 8%=.08
The 10$ is added on because it's a one time exchange and the 8 is multiplied by the x because for every hour you add 8$ to the price and y is the total price at the end depending on x.
