I'm answering this for people don't have to answer

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

Ellen makes and sells bookmarks. she graphs the number of bookmarks sold compared to the total money earned. why is the rate of change for the function graphed to the left?

What is the slope of the line that passes through the points (–9, 2) and (0, 4)? the slope of the line is