Yes, you should be able to do so. I cannot go through all operations for that because Origin 7.5 has very different fitting mechanism from the current Origin 8.x; But you can see the following Help topic, and try it:
Analysis:Curve Fitting>The NLSF Advanced Fitting Tool> Global Fitting of Multiple Datasets Using Shared Parameters
How to fit to TWO functions with shared parameters
Posted - 11/15/2011 : 1:38:30 PM
