The midpoint of y and 31 is -5. what is y

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.

Write two point-slope equations for the line passing through the points (6, 5) and (3, 1)

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+1)