Battery NTC calibration formula help

[Psi]

Hi,

Is anyone able to help me rearrange these two formula to work the other way. I want to figure out what the Rcold and Rhot values will be for any given Rlo and Rh.

I've tried a few times with wolfgram alpha but don't seem to be getting consistent results.

Vcold is 1.99
Vhot is 0.75
Vin is 5

[eneuro]

I've used 1% NTC with 1% 10k in this configuration and by using manufacturer given 3380K for this part NTCM-HP-10K-1%  -55÷125°C; 50mW I;ve made look up table for MPU, so If I wanted I could read directly MPU ADC value and hadrcode in MPU to create desired logic and now I can forget about opamps, but using calculator shown above where I've checked experimantal data by making measurement of NTC resistance at known room temperature using another termometer, voltages thesholds could be estimated, to be able use comparator instead of MPU with ADC 



More about this look up table method and link to this quite nice NTC calculator starting from here:
NTC Thermistor resistance (Li-Ion Charging) ...