Simultaneously fitting three equations to get model parameters?

DATA: Available in the attached excel sheet, T900(1) = cellB3; T900(2) = cellB4; T1000(1) = cellC3 so on and so forth!

Numerator1=((10^(A+(B/T900(1)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(2)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(3)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(4)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(5)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(6)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(7)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(8)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(9)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(10)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(11)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(12)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(13)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(14)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(15)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(16)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(17)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(18)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(19)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(20)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(21)))*4.3018*2.59)/1.386294)+((10^(A+(B/T900(22)))*4.3018*2.59)/1.386294)

Numerator2=((10^(A+(B/T1000(1)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(2)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(3)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(4)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(5)))*4.3018*2.59)/1.386294)+((10^(A+(B/10900(6)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(7)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(8)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(9)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(10)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(11)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(12)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(13)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(14)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(15)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(16)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(17)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(18)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(19)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(20)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(21)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1000(22)))*4.3018*2.59)/1.386294)

Numertor3= ((10^(A+(B/T1100(1)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(2)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(3)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(4)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(5)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(6)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(7)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(8)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(9)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(10)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(11)))*4.3018*2.59)/1.386294)+((10^(A+(B/11900(12)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(13)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(14)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(15)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(16)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(17)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(18)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(19)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(20)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(21)))*4.3018*2.59)/1.386294)+((10^(A+(B/T1100(22)))*4.3018*2.59)/1.386294)

Ratio1 = Numerator1/3.63E-06

Ratio2 = Numerator2/5.72E-06

Ratio3 = Numerator3/8.87E-06

How to find the values of A and B such that (Ratio1+Ratio2+Ratio3)=3? I would like the values which are close to A=-1.838;B=5347. Is there a code that I can do this with? Thank you for your help!

Answer 1

[Roger Stafford]

You apparently have just one equation, namely "Ratio1+Ratio2+Ratio3=3", and two unknowns, A and B. In general such a situation will allow infinitely many solution pairs. Which one are you interested in?

[AluAl]

I would like the values which are close to A=-1.838;B=5347. Is there a code that I can do this with? Thank you for your help!