Please help with the following macroeconomics question:

2. Consider three processes that change through time: x (t), y (t) and i (t). The first two processes grow at the constant exponential rates g (x) and g (y) respectively. Calculate the growth rate of g (=) in the following cases, where & is some constant. a) z(t) = 120 b) =(t) = (x(t))*y(t), c) z(t) = (x(t))*/(y(t))*-1, d) z(t) = 1/y(t)