9a and it has a little 2 at top of the a i dont understand how to solve

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?

If you have a set of parallel lines a and b cut by transversal x, if angle 1 = 167 degrees, what is angle 4 and why. also what is the measure of angle 5 and why? you need to use the names of the angle relationship and explain.

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.