While looking into the better indicator of how miserable it feels outside, either dew point or relative humidity, I came across this statement:

The optimum combination for human comfort is a dewpoint of about 60 F and a RH of between 50 and 70% (this would put the temperature at about 75 F).

Source: http://www.theweatherprediction.com/habyhints/190/

This led me to this calculator that will calculate the temperature given relative humidity and dew point - for example a dew point of 70 degrees F and a relative humidity of 90% results in a temperature of 73.11 degrees F. The web site for this calculator says the values are based on the August-Roche-Magnus approximation and gives the following equation to calculate temperature:

T: =243.04*(((17.625TD)/(243.04+TD))-LN(RH/100))/(17.625+LN(RH/100)-((17.625TD)/(243.04+TD)))

Given the equation I'm still having a hard time figuring out how the temperature is being calculated. Can somebody please explain how temperature is being calculated in simple terms?