how to fit two curves using lsqcurvefit or any method

I need to know how to fit two curves with different data.

The modeling equations are with same parameters. i.e. y1 = p(1)*x^-p(2) + real ( p(3)/((1+x*p(4))^p(5))) y2 = p(1)*x^-p(2) + imag( p(3)/((1+x*p(4))^p(5))) + p(6)*x

need to find optimum values for the parameters p(1), p(2), p(3), p(4),p(5) which can fit both curves.

Thank you.