How can I easily obtain a curve fit parameters for several data?

I have sets of data of dependent variables stored in matrices A1 and A2 of size 36 by 12 and the independent variable data [are] stored in a vector L of size 1 by 12. My task is to fit each of the row of A1 and A2 to the models:

model for A1 (exponential)

A=a*exp (b*x) + c*exp (d*x)

Model for A2 (quadratic or cubic polynomial)

I have made some trials to fit this data one at a time but it seems this method is somewhat time consuming. Besides, the best polynomial fit for A2 changes from quadratic to cubic at some point. I would like to know if there is a fast and easy method to complete this task. Thanks in advance for your response.