PLEASEEE HELP QUICK find the midpoint of (5,11) and (4,-2)

You can find the constant of proportionality by finding the ratio of

For f(x) = 3x+1 and g(x) = x2 - 6, find (g/f)(x)

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?