2 3 7z 6 ) 1 3 2z 9 July 8, 2019 16 32 64 128 2 3 7z 6 )+ 1 3 2z 9 2) ((z + 6)/(3z + 9) - 1/(z + 3)) / ((z + 2)/(27z)) 3 7z-z=0.54
