The new book was only $19.50 but it was another 60% if the author signed it. what will my book cost with an author's signature. (show your work)

Trigonometry hellllllpppppppp asap

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.