Read this and answer please

Plot the points (0,6), (3,15.8), and (9.5,0) using the graphing tool, and find the function

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.

Multiply. write your answer in simplest form. 3/8 x 5/7