For the following regression models discuss the estimation techniques (linear, log-linear, non linear). Linearize the models if needed.
a) yt = bo(1 + x)b1teut
b) yt = ebox1b1x2b2 + ut
c) yt = bo + b1xb2 + ut
d) yt = b1 + b2(x2t - b3x3t) + b4(x4t - b3x5t) + et