does anybody know how 1666=√[2(6.674e-11)(7.342e22)( (1/1738000) - (1(/1738000+h)))] become 1666² = 2(6.674e-11)(7.342e22)( (1/1738000) + (1(/1738000+h))). How does the minus between 8000) and (1(/1 becomes plus ?

First, we should consider the typo: what does 1(/ mean?