I'll do the second problem for you to give you an idea how to approach the third problem.
z = xln(x)
Take the natural log of both sides and use the property that ln(ab) = b ln(a).
ln(z) = ln(xln(x)) = ln(x) ln(x) = [ln(x)]2
Now differentiate to get
z'/z = 2 [ln(x)] 1/x
z' = z 2 [ln(x)] 1/x = 2 xln(x) ln(x)/x
Apply the same technique to the third problem. For the first problem the first step is to use the property of the log that I used above.